Part evaluation based upon system natural frequency

A part evaluation tool is disclosed and which may be used to assess a part-under-test for use in a system. A plurality of natural frequencies for a system operated at a first steady-state operational are identified. A vibrational response of a part-under-test is acquired, and resonance frequencies within this vibrational response are identified. Resonance frequencies of the part-under-test are compared with the identified natural frequencies for purposes of classifying the part as compliant (e.g., suitable for use in the system) or non-compliant (e.g., not suitable for use in the system).

FIELD OF THE INVENTION

The present invention generally relates to the evaluation of a part and, more particularly, to evaluating a part that is used by a system that is operated at one or more steady-state operational frequencies.

BACKGROUND

A variety of techniques have been developed in which parts may be tested “nondestructively,” meaning that the testing methodology enables defects to be identified without causing damage to the part. Examples of such nondestructive-testing methodologies include acoustic techniques, magnetic-particle techniques, liquid-penetrant techniques, radiographic techniques, eddy-current testing, and low-coherence interferometry, among others. There are various known advantages and disadvantages to each of these categories of testing methodologies, which are accordingly used in different environments.

Nondestructive-testing methods that use acoustic radiation generally operate in the ultrasonic range of the acoustic spectrum, and are valuable for a number of reasons. Such techniques are sensitive, for example, to both surface and subsurface discontinuities, enabling identification of defects both within the bulk and near the surface of a part. The depth of penetration for defect detection is generally superior to many other nondestructive-testing methodologies, and the techniques are highly accurate not only in determining the position of a defect, but also in estimating its size and shape.

SUMMARY

A first aspect of the present invention is directed to the evaluation of a part. A plurality of natural frequencies associated with a system are identified, where these natural frequencies are generated by or exist during operation of the system at a first steady-state operational frequency (which hereafter may be referred to as “selected natural frequencies”), and where the system includes a first part. A first vibrational response of a part-under-test (e.g., a candidate for use as the first part in the system) is acquired using at least one sensor, and a plurality of resonance frequencies of the part-under-test are identified in this first vibrational response (which hereafter may be referred to as “selected resonance frequencies”). The selected resonance frequencies of the part-under-test are compared with the selected natural frequencies of the system, and the part-under-test is classified based upon this comparison.

A number of feature refinements and additional features are applicable to the first aspect of the present invention. These feature refinements and additional features may be used individually or in any combination. The following discussion is applicable to at least the first aspect, up to the start of the discussion of a second aspect of the present invention.

At least one natural frequency that is compared to one or more resonance frequencies of the part-under-test, in accordance with the first aspect: 1) may be a natural frequency of an entirety of the system; 2) may be a natural frequency of a sub-system of the system; and/or 3) may be a natural frequency of an individual component of the system. Any appropriate number of natural frequencies may be identified and that are associated with operation of the system at the first steady-state operational frequency, including two or more natural frequencies. The multiple natural frequencies that are identified in association with operation of the system at the first steady-state operational frequency may be acquired in any appropriate manner, such as by modeling operation of the system at the first steady-state operational frequency (e.g., using a third aspect of the present invention, addressed below, to update a computer model of the system), such as by functional testing of the system (e.g., via operation of a prototype of the system at the first steady-state operational frequency), or both.

The comparison of the selected resonance frequencies of the part-under-test with the selected natural frequencies of the system may entail establishing/setting a separate natural frequency threshold for each selected natural frequency that is to be compared with the selected resonance frequencies of the part-under-test. Each natural frequency threshold may define a frequency range of any appropriate magnitude. One embodiment has each natural frequency threshold being set or established based upon information provided by an original equipment manufacturer. In any case, each natural frequency threshold that is utilized for the resonance frequency comparison may be acquired from any appropriate data source, such as by modeling operation of the system at the first steady-state operational frequency (e.g., using a third aspect of the present invention, addressed below, to update a computer model of the system), such as by functional testing of the system (e.g., via operation of a prototype of the system at the first steady-state operational frequency), or both.

The part-under-test may be of any appropriate type, for instance a new production part, an in-service part, an original equipment manufacturer or OEM part, a parts manufacturer approval or PMA part, or one that is a candidate for approval as a PMA part. Moreover, the part-under-test may be one that is being evaluated for use as the first part in the system. This first part may be one that moves at least at some point in time during the operation of the system at the first steady-state operational frequency, may be one that is stationary at least at some point in time during the operation of the system at the first steady-state operational frequency, or both. One embodiment has the first part moving throughout operation of the system at the first steady-state operational frequency. Another embodiment has the first part remaining stationary (at least relative to a remainder of the system) throughout operation of the system at the first steady-state operational frequency.

A separate natural frequency threshold may be associated with each selected natural frequency for the system and that is then compared with the selected resonance frequencies of the part-under-test in accordance with the first aspect. The comparison may entail comparing each selected resonance frequency of the part-under-test with the natural frequency threshold for each selected natural frequency of the system. If each selected resonance frequency of the part-under-testis outside of the natural frequency threshold for each selected natural frequency of the system, the part-under-test may be classified as a “compliant part.” Otherwise, the part-under-test may be classified as a “non-compliant part.”

A vibrational response of the part-under-test may be acquired at one or more times for comparison of the selected resonance frequencies of the part-under-test with the selected natural frequencies of the system. For instance, the method in accordance with the first aspect may be conducted on a part-under-test before the part is ever put into service into the system (i.e., a new production part), after the part has already been in incorporated by the system for any appropriate amount of time and during which the system was operated at least at the first steady-state operational frequency (i.e., an in service part), or both. The first aspect may be utilized in relation to acquisition of the vibrational response of the part-under-test at each of these times. All features of the first aspect relating to the first vibrational response and the part-under-test are applicable to each vibrational response that may be acquired on the part-under-test for comparison with the selected natural frequencies of the system.

Each vibrational response of the part-under-test may be acquired in any appropriate manner. At least one vibrational response of the part-under-test, more specifically its selected resonance frequencies, is compared with the selected natural frequencies of the system, all for purposes of classifying the part-under-test. The first vibrational response of the part-under-test may also be used for other purposes. For instance, the resonance frequencies in the first vibrational response of the part-under-test may be compared with a computer model of the first part for the system, and this comparison may be used to update the computer model of the first part (for instance, where this computer model of the first part is used as the data source for one or more other “tests” that may be conducted on the part-under-test, as discussed below).

One embodiment has the first vibrational response of the part-under-test being acquired through execution of a resonance inspection of the part-under-test. Features of such a resonance inspection are addressed in more detail below. Although it may be possible for a resonance inspection to be conducted on a part when incorporated by the system (e.g., an in situ resonance inspection of the part), it may be beneficial for the resonance inspection to be conducted on the part after it has been removed from the system (e.g., at a time when the part is disassociated from the system).

The comparison of the selected resonance frequencies in the first vibrational response of the part-under-test, with the selected natural frequencies of the system, may be characterized as one “test” for purposes of the first aspect. The first vibrational response of the part-under-test may be used in conjunction with at least one other “test,” although each of the following tests may be used independently of the first aspect as well.

The first vibrational response of the part-under-test may be tested against a sort (e.g., a resonance inspection that utilizes such a sort). A “sort” may be characterized as an algorithm or a combination of algorithms that is used to determine if frequency-based criteria (i.e., one or more frequency-based criterion) exist in the frequency response of the part-under-test. Such a sort may be based upon data from a resonance inspection that was previously conducted on one or more parts, may be based upon computer modeling (e.g., as addressed in the third aspect in relation to an updated computer model for a part), may be based upon functional testing, or any combination thereof. This sort may be configured for the assessment of new production parts, may be configured for the assessment of in-service parts (or any other part for that matter), or may be configured to determine if a particular part is aging normally or abnormally.

The classification of the part-under-test may be based upon both the comparison of the selected resonance frequencies of the part-under-test with the selected natural frequencies of the system, along with the testing of the first vibrational response against a sort in accordance with the foregoing. For instance, the part-under-test may be characterized as a “compliant part” if both: 1) each resonance frequency of the selected resonance frequencies of the part-under-test is outside of a separate natural frequency threshold for each of the selected natural frequencies of the system; and 2) the execution of the sort on the first vibrational response yields a sort result in the form of a “compliant part classification” (e.g., the first vibrational response of the part-under-test passes the sort and where the sort is configured to identify one or more predetermined characteristics/attributes of a compliant part; the first vibrational response fails the sort and where the sort is configured to identify one or more predetermined characteristics/attributes of a non-compliant part). Conversely, a part-under-test may be characterized as a “non-compliant part” if one or more of the following exits: 1) at least one resonance frequency of the selected resonance frequencies of the part-under-test is within the natural frequency threshold of at least one of the selected natural frequencies of the system; or 2) the execution of the sort on the first vibrational response yields a sort result in the form of a “non-compliant part classification” (e.g., the first vibrational response passes the sort and where the sort is configured to identify one or more predetermined characteristics/attributes of a non-compliant part; the first vibrational response fails the sort and where the sort is configured to identify one or more predetermined characteristics/attributes of a compliant part).

Another test that may use the first vibrational response of the part-under-test includes comparing the first vibrational response to at least one resonance standard. Such a resonance standard may be based upon data from a resonance inspection that was previously conducted on one or more parts, or may be based upon computer modeling (e.g., as addressed in the third aspect in relation to an updated computer model for a part). This comparison with one or more resonance standards may be used in the assessment of both new production parts and in-service parts (or any other part for that matter), and furthermore may be used to determine if a particular part is aging normally or abnormally.

The classification of the part-under-test may be based upon both the comparison of the selected resonance frequencies of the part-under-test with the selected natural frequencies of the system, along with the comparison of the first vibrational response to at least one resonance standard. For instance, the part-under-test may be characterized as a “compliant part” if both: 1) each selected resonance frequency of the part-under-test is outside of a separate natural frequency threshold for each of the selected natural frequencies of the system; and 2) the first vibrational response of the part-under-test complies with at least one resonance standard that is associated with a compliant part (and/or if the first vibrational response of the part-under-test fails to comply with any resonance standard that is associated with a non-compliant part). Conversely, a part-under-test may be characterized as a “non-compliant part” if one or more of the following exits: 1) at least one of the selected resonance frequencies of the part-under-test is within the natural frequency threshold of at least one of the selected natural frequencies of the system; or 2) the first vibrational response of the part-under-test fails to comply with at least one resonance standard that is associated with a compliant part (and/or if the first vibrational response of the part-under-test complies with at least one resonance standard that is associated with a non-compliant part).

Yet another test that may use the first vibrational response of the part-under-test includes comparing each selected resonance frequency of the part-under-test to one or more resonance frequency thresholds, including where each resonance frequency threshold may be in the form of a certain frequency range. A “compliant part” may be one that has a separate resonance frequency in the first vibrational response for each specified resonance frequency threshold (e.g., where there is a separate resonance frequency from the first vibrational response within a different frequency range associated with each resonance frequency threshold). The classification of the part-under-test may be based upon both the comparison of the selected resonance frequencies of the part-under-test with the selected natural frequencies of the system, as well as the comparison of resonance frequencies of the part-under-test with the resonance frequency thresholds that are required for a compliant part classification. For instance, the part-under-test may be characterized as a “compliant part” if both: 1) each selected resonance frequency of the part-under-test is outside of a separate natural frequency threshold for each of the selected natural frequencies of the system; and 2) the first vibrational response includes a separate resonance frequency that complies with each resonance frequency threshold that is specified for a compliant part classification (e.g., there is a separate resonance frequency from the first vibrational response within the frequency range associated with each resonance frequency threshold that has been specified). Conversely, a part-under-test may be characterized as a “non-compliant part” if one or more of the following exits: 1) at least one selected resonance frequency of the part-under-test is within the natural frequency threshold of at least one of the selected natural frequencies of the system; or 2) at least one resonance frequency threshold that is required for a compliant part classification is not satisfied by any resonance frequency in the first vibrational response (e.g., the first vibrational response does not include a resonance frequency within the frequency range associated with at least one of the resonance frequency thresholds that has been specified).

Each resonance frequency threshold or range that is utilized by the first aspect may be determined/established in any appropriate manner. For instance, one or more resonance frequency ranges for use by the first aspect: 1) may be identified or otherwise selected from the resonance inspections results of a plurality of parts; 2) may be identified or otherwise selected from a computer model of the first part (e.g., as addressed in the third aspect in relation to an updated computer model for a part); or 3) from functional testing of one or more parts.

The part-under-test may also be tested to determine if the part-under-test resonates at least substantially the same as at least one compliant part. A part-under-test may be classified as a “compliant part” if it resonates at least substantially the same as least one other part that has previously been determined to be a compliant part. The classification of the part-under-test may be based upon both the comparison of the selected resonance frequencies of the part-under-test with the selected natural frequencies of the system, along with the noted resonation comparison. For instance, the part-under-test may be characterized as a “compliant part” if both: 1) each of the selected resonance frequencies of the part-under-test is outside of a separate natural frequency threshold for each of the selected natural frequencies of the system; and 2) the part-under-test resonates at least substantially the same as at least one other compliant part. Conversely, a part-under-test may be characterized as a “non-compliant part” if one or more of the following exits: 1) at least one selected resonance frequency of the part-under-test is within the natural frequency threshold of at least one of the selected natural frequencies of the system; or 2) the part-under-test fails to resonate at least substantially the same as at least one other compliant part.

A number of implementations are envisioned in relation to the first aspect. One is that an original equipment manufacturer may specify the requirements associated with the classification of the part-under-test (e.g., to establish a compliant part classification or the like), and the part-under-test may be from a non-OEM entity (e.g., the first aspect may be configured for the assessment of non-OEM parts). The first aspect may be implemented to assess multiple designs of the same part, where each of these designs may be encompassed by a common product specifications standard. In certain cases, a product specifications for the first part of the system may be updated from time to time. The first aspect may be used to assess a first part-under-test that is in accordance with a first product specifications standard for the first part of the system, and furthermore may be used to assess a second part-under-test that is in accordance with a second product specifications standard for the first part of the system, where the second product specifications standard is an update of the first product specifications standard. The first aspect may be used to determine if an update of a product specifications standard for the first part is appropriate.

There may be situations where the first part for the system is completely redesigned. The first aspect may be used to assess the redesign, for instance to determine if the redesign of the first part is still suitable for implementation into the system. Of course the first aspect may be used to assess an original design of a part for the system as well. The first part for the system may be repaired or refurbished. The first aspect may be used to determine that the first part is still suitable for incorporation back into the system after having been repaired or refurbished.

The first aspect is also applicable to assessing the manufacture of parts for use as a first part in the system. It is possible that different manufacturing protocols may be used to manufacture the same part for use as the first part in the system. A first part-under-test may be manufactured according to a first manufacturing protocol that is within a manufacturing specifications standard for the first part, while a second part-under-test may be manufactured according to a second manufacturing protocol. This second manufacturing protocol may be different from the first manufacturing protocol, but the second manufacturing protocol may still be within the manufacturing specifications standard for the first part. The first aspect may be used to assess parts that are manufactured in accordance with the first manufacturing protocol, and also may be used to assess parts that are manufactured in accordance with the second manufacturing protocol. The first aspect may also be utilized to validate a manufacturing process for parts to be used as a first part in the system (e.g., to confirm that parts that are manufactured in accordance with such a manufacturing process are suitable for use in the system), whether in the form of an original manufacturing process/protocol or a revised/modified/updated manufacturing process/protocol.

A second aspect of the present invention is directed to the evaluation of a part. A first resonance inspection is conducted on a first part, where a first frequency response of the first part is acquired by exciting the first part at a plurality of input frequencies. The first frequency response of the first part is tested against a sort. This sort is based upon resonance inspection results of at least one part, where this part has passed operational certification testing for purposes of validating a design of the part. The first part is assigned to a compliant part classification if the sort provides a compliant part classification sort result. In order for the first part to be assigned a compliant part classification, the first frequency response of the first part must include a first resonance frequency that is within a first frequency range. That is, the sort is configured to require a first resonance frequency that is within a first frequency range in order for the sort to yield a compliant part classification sort result.

A number of feature refinements and additional features are applicable to the second aspect of the present invention. These feature refinements and additional features may be used individually or in any combination. The following discussion is applicable to at least the second aspect, up to the start of the discussion of a third aspect of the present invention. Initially, this second aspect may be used in combination with the above-noted first aspect.

The first part may be assigned to a non-compliant part classification if the sort provides a non-compliant part classification sort result. A non-compliant part classification sort result may be generated by the sort if the first frequency response of the first part lacks or fails to include a resonance frequency within the first frequency range.

One embodiment has the sort being used to evaluate parts only after a determination has been made that the part actually passed the operational certification testing. So long as the part has in fact passed operational certification testing, the resonance inspection results that are used to define the sort for the second aspect may be based upon: 1) a resonance inspection of such a part after having completed the operational certification testing but before this part has actually been put into service; or 2) a resonance inspection of such a part after having completed the operational certification testing, and furthermore after this part has actually been put into service for a certain period of time (e.g., an in-service part that has itself also previously passed operational certification testing).

The sort may be configured to also require a separate resonance frequency within each of a plurality of different frequency ranges, including where none of these different frequency ranges overlap to any extent. For instance, the sort may be configured to require a second resonance frequency within a second frequency range. One embodiment has the first frequency range being completely separate from the second frequency range, or where there is no overlap between the first frequency range and the second frequency range (e.g., the first and second frequency ranges may be selected such that there is not a single frequency that exists in both the first frequency range and the second frequency range). In any case, in order for the first part to be assigned a compliant part classification in this example, the first frequency response of the first part must include a first resonance frequency that is within the first frequency range, and the first frequency response of the first part must include a second resonance frequency that is within the second frequency range. That is, the sort may be configured to require a first resonance frequency that is within a first frequency range and to require a second resonance frequency that is within a second frequency range, all in order for the sort to yield a compliant part classification sort result. Conversely, a non-compliant part classification sort result may be generated by the sort if one or more of the following exits: 1) the first frequency response of the first part lacks or fails to include a first resonance frequency within the first frequency range; 2) if the first frequency response of the first part lacks or fails to include a second resonance frequency within the second frequency range; or 3) the first frequency response of the first part lacks or fails to include a first resonance frequency within the first frequency range, and the first frequency response of the first part also lacks or fails to include a second resonance frequency within the second frequency range.

A third aspect of the present invention pertains to modeling, for instance for purposes of identifying one or more natural frequencies of a system for use in conjunction with the above-noted first aspect. A frequency response of a part-under-test is acquired. A first transfer function is applied to this first frequency response to define a second frequency response (or a first transformed frequency response). This second frequency response is associated with the part-under-test being vibrated in “free space.” That is, the first transfer function transforms or translates the frequency response of the part-under-test (where the part-under-test may be in contact with one or more structures) for when the part-under-test is in free space (e.g., to predict how the part-under-test would respond, on a vibrational basis, when in free space). The second frequency response of the part-under-test is then compared to a modeled frequency response from a computer model of a part (e.g., associated with the part-under-test), and the computer model of the part is then updated accordingly (e.g., so that the computer model of the part more closely approximates the part-under-test at least on a vibrational or frequency response basis), and which may be referred to as an updated computer model of the part. A second transfer function is then applied to a modeled frequency response of the updated computer model of the part to define a third frequency response (or a second transformed frequency response). This third frequency response is associated with the part-under-test as it would vibrate when installed in a system and operated at a first steady-state operational frequency. That is, the second transfer function transforms or translates the frequency response of the part-under-test for the case where the part-under-test has now been installed back in the system (where the part-under-test may be in contact with one or more structures of the system). This may then be used to update a computer model for the system.

A number of feature refinements and additional features are applicable to the third aspect of the present invention. These feature refinements and additional features may be used individually or in any combination. The following discussion is applicable to at least the third aspect. Initially, this third aspect may be used in combination with the above-noted first aspect, alone or where the second aspect has also been implemented in conjunction with the first aspect.

The updated computer model of the part (corresponding with the part-under-test) may be used for any appropriate purpose, including as a data source for a resonance inspection. For instance, a sort may be based upon this updated computer model of the part, or a resonance standard may be based upon this updated computer model of the part. The updated computer model of the system also may be used for any appropriate purpose. For instance, the updated computer model of the system may be used to identify a plurality of natural frequencies of the system when the system is operated at a first steady-state operational frequency, such as for use in conjunction with the first aspect. The updated computer model of the system could also be used to establish or select a natural frequency threshold for each of a plurality of these natural frequencies of the system, such as for use in conjunction with the first aspect.

The various aspects of the present invention each may be implemented as a method and/or as an evaluation system or tool. Vibrational response data for use by the present invention may be acquired using a resonance inspection tool (although the resonance inspection tool is not required to actually perform a resonance inspection for purposes of the present invention). The vibrational data on a part being assessed for purposes of the present invention may be generated by exciting the part at a plurality of input frequencies and obtaining a frequency response of the part (e.g., to acquire/assess resonance data). This may be characterized as obtaining a whole body frequency response of the part using a number of different drive or input frequencies.

Data acquisition for purposes of the present invention may utilize a first transducer that excites or drives a part at multiple frequencies (e.g., by sweeping through a predetermined range of frequencies in any appropriate manner), along with at least one other transducer that measures the frequency response of this part to such excitations or drive frequencies (e.g., thereby encompassing using two or more “receiver” transducers). Any number of frequencies may be used to excite the part, and the excitation frequencies may be input to the part in any appropriate pattern and for any appropriate duration. Another option is to use a single transducer for acquiring vibrational data on the part. In this case, a transducer may drive the part at a certain frequency for a certain amount of time, and thereafter this same transducer may be used to obtain the frequency response of the part (e.g., after terminating the driving of the transducer at an input frequency). This may be repeated for multiple input or drive frequencies.

Any appropriate combination of excitation or drive frequencies may be used for vibrational data acquisition for use in conjunction with the present invention. Each transducer that is used to perform an inspection may be of any appropriate size, shape, configuration, and/or type. Although vibrational data acquisition could possibly be performed in situ (e.g., with the part in an installed condition or state), vibrational data acquisition will more typically be undertaken prior to installing a part for its end-use application or with the part being in an uninstalled condition or state.

Vibrational data acquisition in conjunction with the present invention may entail exciting a part-under-test using at least one drive transducer that is in contact with the part. Another option is to excite a part-under-test using at least one drive transducer that is maintained in spaced relation to the part-under-test throughout the acquisition of vibrational data. In one embodiment, such a drive transducer (e.g., a drive transducer that is spaced from the part-under-test for the inspection) may be in the form of a laser.

Any feature of the present invention that is intended to be limited to a “singular” context or the like will be clearly set forth herein by terms such as “only,” “single,” “limited to,” or the like. Merely introducing a feature in accordance with commonly accepted antecedent basis practice does not limit the corresponding feature to the singular (e.g., indicating that a resonance inspection system/tool utilizes “a frequency response transducer” alone does not mean that the resonance inspection system/tool utilizes only a single frequency response transducer). Moreover, any failure to use phrases such as “at least one” also does not limit the corresponding feature to the singular (e.g., indicating that a resonance inspection system/tool utilizes “a frequency response transducer” alone does not mean that the resonance inspection system/tool utilizes only a single frequency response transducer). Use of the phrase “at least generally” or the like in relation to a particular feature encompasses the corresponding characteristic and insubstantial variations thereof (e.g., indicating that a structure is at least generally cylindrical encompasses the structure being cylindrical). Finally, a reference of a feature in conjunction with the phrase “in one embodiment” does not limit the use of the feature to a single embodiment.

DETAILED DESCRIPTION

Various applications of resonance inspection (e.g., resonance ultrasound spectroscopy; process compensated resonance testing) are addressed herein. Various principles that may relate to resonance inspection are addressed in the following U.S. patents, the entire disclosures of which are incorporated by reference in their entirety herein: U.S. Pat. Nos. 5,408,880; 5,425,272; 5,495,763; 5,631,423; 5,641,905; 5,837,896; 5,866,263; 5,952,576; 5,965,817; 5,992,234; and 6,199,431.

One embodiment of a resonance inspection tool or system (e.g., for accommodating resonant ultrasound spectroscopy measurement with a plurality of sensors; for process compensated resonance testing) is illustrated inFIGS. 1 and 2, and is identified by reference numeral 5. The resonance inspection tool5includes a computer10that provides for control of a synthesizer12and an analog to digital converter11for each data input channel connected to each receiving or response transducer22,24of the resonance inspection tool5. Transducer22has an output on line31, while transducer24has an output on line25.

Synthesizer12may have a frequency range from greater than 0 to 20 M Hertz. Other frequency ranges may be appropriate. Synthesizer12provides two outputs which are the frequency F1at output14and a second output which is the frequency F2at line16. In one embodiment, the frequency F2is either F1plus a constant frequency such as 1000 Hertz for heterodyne operation of the receiver, or at F1for homodyne operation. A first transducer18(e.g., the input or driving transducer) is excited at a frequency F1by synthesizer12. Transducer18provides vibration (e.g., ultrasonic) to an object20to be tested via resonance inspection.

The response of the object20is then received by two separate output transducers22and24. The circuitry from the output transducer22and A/D converter11can be identical to circuitry between output transducer24and A/D converter11. For this reason, only the circuitry between output transducer22and A/D converter11will be discussed below. The times one (.times.1) amplifier26is connected to the output transducer22, provides current for transformer28, and has a feedback27.

The output of transducer22is connected to a receiver41(FIG. 2). Receiver41is used for the purpose of providing amplification and noise rejection in the circuit between output transducer22and A/D converter11. The output A (line40) is applied to the A/D converter11within the computer10. The A/D converter11provides an A/D conversion for each of lines40and42. The converted information is then entered into a file which consists of the measured frequency, the amplitude of A, the amplitude of B, the amplitude of A plus B, and the amplitude of A minus B. This file is then used for further analysis of the spectrum to determine characteristics of a part20being tested.

The times one (.times.1) amplifier26provides feedback to an inner coaxial cable shield30which surround the lead from transducer22to amplifier26. Shield30is another grounded shield which can also be used for noise suppression. The outer surrounding coaxial cable is not shown inFIG. 1. If lead31is short, the shield30may be omitted because capacitance will not be too large. The purpose of the inner shield30is to provide a cancellation of capacitance of the lead31.

The transformer28may be a 4:1 step-down transformer used for impedance matching to the input of amplifier32. In this regard, it should be noted that the output impedance of amplifier26may be much lower than the output impedance of transducer22. This provides for the power gain and the necessary feedback to shield30. The amplifier32may have a gain factor of 100:1 or a 40 db gain. Other gain factors may be appropriate. The amplifier26may be a broad-band amplifier having a band pass on the order of 50 M Hertz.

Mixer34has an output signal (e.g., a 1 K Hertz signal) having a magnitude which is proportional to the magnitude of the frequency F1provided on line14from synthesizer12. The function of the synthesizer12is to provide a point-by-point multiplication of instantaneous values of inputs on lines16and33. The mixer34also has many high frequency output components which are of no interest. The high frequency components are therefore filtered out by the low-band pass filter38which is connected to mixer34by line36. Filter38serves to clean-up the signal from mixer34and provide a voltage on line40which is only the output signal at an amplitude which is proportional to the amplitude of the output31of transducer22.

Operation of the resonance inspection tool5will be briefly described in relation to measurement steps performed by measurement of the output of either transducer22or transducer24controlled by computer10. A measurement cycle may be initiated, and provides initialization for the frequency F and the desired frequency step. The frequency step may be 1 Hertz or any other frequency selected for the measurement. Although a constant frequency step may be utilized, the frequency step may be determined by any appropriate algorithm. In one embodiment, the frequency step is determined by determining the start frequency and the stop frequency, and dividing the frequency difference by the number of steps desired for the measurement. In any case, the synthesizer12is configured to provide a plurality of input or drive frequencies to transducer18.

Once a signal is picked up by the receiver (i.e., an output on line33), a pause for ring delay there is a provided. The pause for ring delay may be on the order of 30 milliseconds, although other ring delays can be used if the object under test20has resonances that are narrower than a few Hertz. The purpose of the pause is to give the object20an opportunity to reach its steady state magnitude in response to a steady input from transducer18. The pause time is time after the frequency is applied and before detection is initiated.

After the ring delay is complete, analog-to-digital converter11provides an output that can be used by the data recording computer. The output of the A/D conversion is then written to a file by the computer10for the purpose of analysis of the data by another program. Data comprising the unique signature or characterizing of the object20is written into file as it is created. Reading may be stopped when a read frequency is present and step66stops the program. Once information is entered into file, subsequent processing can be used to generate a signature or characterize the object20such as the resonant magnitudes, the sum of resonant magnitudes, the difference resonant magnitudes, or other manipulations of the multiple channel multiple frequency measurement which is used to perform the unique signature of the object20. The magnitude of the outputs at each sensor location for each resonance frequency may be compared.

Another embodiment of a resonance inspection tool or system is illustrated inFIG. 3and is identified by reference numeral 100. The resonance inspection tool100includes a signal generator102of any appropriate type, at least one transducer of any appropriate type that interfaces with a part120(e.g. via physical contact) that is to undergo a resonance inspection (e.g., transducer104), and a computer108. The computer108may include what may be characterized as an assessment module110(e.g., incorporated/embodied by a non-transitory computer-readable storage medium). Generally, the assessment module110may be configured to evaluate the results of a resonance inspection, for instance for purposes of determining whether the part120should be accepted or rejected by the resonance inspection tool100, determining whether the part120is at an end-of-life state or condition, or the like. A part120that is “accepted” by the resonance inspection tool100may mean that the resonance inspection tool100has determined that the part120may be put into service (e.g., utilized for its intended purpose(s) and/or used according to its design specifications). In one embodiment, a part120that has been accepted by the resonance inspection tool100means that the tool100has determined that the part120is free of defects, is not in an end-of-life condition or state, is aging normally, or any combination thereof. A part120that is “rejected” by the resonance inspection tool100may mean that the resonance inspection tool100has determined that the part120should not be put into service (e.g., should not be utilized for its intended purpose(s) and/or should no longer be used according to its design specifications). In one embodiment, a part120that has been rejected by the resonance inspection tool100means that the tool100has determined that the part120includes at least one defect, is at or near an end-of-life condition or state, is aging abnormally, or any combination thereof.

A part120that is analyzed or assessed by the resonance inspection tool100may be of any appropriate size, shape, configuration, type, and/or class. For purposes of the resonance inspection tool100, there could be two part classes. One part class includes new production parts—newly manufactured parts that have not yet been released from production (e.g., parts that have not been shipped for use by an end user or customer). New production parts include parts that may have undergone at least some post-production testing of any appropriate type (including without limitation a resonance inspection). Another part class includes in-service parts—parts that have been released from production for use in one or more end-use applications. An “in-service part” in the context of the embodiments to be addressed herein encompasses a part that has been used to at least some extent after having been released by the manufacturer. An in-service part may be a part that has been put into use by a party other than the manufacturer (e.g., a customer or end user). Although an in-service part could be used autonomously or independently of any other parts, an in-service part may be incorporated by an assembly or system (e.g., a turbine blade (an in-service part) in a jet engine (an assembly or system)).

The signal generator102generates signals that are directed to the transducer104for transmission to the part120in any appropriate manner/fashion (e.g., via physical contact between the transducer104and the part120). Signals provided by the signal generator102are used to mechanically excite the part120(e.g., to provide energy to the part120for purposes of inducing vibration). Multiple frequencies may be input to the part120through the transducer104in any appropriate manner. This may be characterized as “sweeping” through a range of frequencies that are each input to the part120, and this may be done in any appropriate manner for purposes of the resonance inspection tool100. Any appropriate number/range of frequencies may be utilized, and any appropriate way of progressing through a plurality of frequencies (e.g., a frequency range) may be utilized by the resonance inspection tool100.

In one embodiment, at least one other transducer106is utilized in the resonance inspection of the part120using the resonance inspection tool100ofFIG. 3, including where two transducers106are utilized (e.g., in accordance with the embodiment ofFIGS. 1 and 2noted above). Each of the transducers106, as well as the input or drive transducer104, may be in physical contact with the part120. It may be such that the part120is in fact entirely supported by the transducer104and any additional transducers106. Each transducer106that is utilized by the resonance inspection tool100is used to acquire the frequency response of the part120to the frequencies input to the part120by the drive transducer104, and therefore each transducer106may be characterized as an output or receiver transducer106.

Another embodiment of the resonance inspection tool100ofFIG. 3utilizes only the transducer104. That is, no additional transducers106are utilized by the resonance inspection tool100in this case, and therefore the transducer106is presented by dashed lines inFIG. 3. In this case, the transducer104is used to input a drive signal to the part120(e.g., to excite the part120at a plurality of different frequencies), and is also used to acquire the frequency response of the part120to these input drive frequencies. For instance, a first drive signal at a first frequency (from the signal generator102) may be transmitted to the part120through the transducer104, the transmission of this first drive signal may be terminated, and the transducer104may be used to acquire a first frequency response of the part120to this first drive signal (including while a drive signal is being transmitted to the part120). The signal generator102may also be used provide a second drive signal at a second frequency to the transducer104, which in turn transmits the second drive signal to the part120, the transmission of this second drive signal may be terminated, and the transducer104may once again be used to acquire a second frequency response of the part120to this second drive signal (including while a drive signal is being transmitted to the part120). This may be repeated any appropriate number of times and utilizing any appropriate number of frequencies and frequency values. One or more drive signals may be sequentially transmitted to the part120by the signal generator102and transducer104, one or more drive signals may be simultaneously transmitted to the part120by the signal generator102and transducer104, or any combination thereof.

The frequency response of the part120is transmitted to the computer108of the resonance inspection tool100ofFIG. 3. This computer108may be of any appropriate type and/or configuration, and is used by the resonance inspection tool100to evaluate the part120in at least some fashion (e.g., to determine whether to accept or reject the part120). Generally, the part120is vibrated by the transducer104according to a predetermined signal(s), and the part120is evaluated by the resulting vibrational response of the part120. For instance, this evaluation may entail assessing the part120for one or more defects of various types, assessing whether the part120is at or near the end of its useful, life, assessing whether the part120is aging normally or abnormally, or any combination thereof.

The computer108may incorporate and utilize the above-noted assessment module110to evaluate the response of the part120to a resonance inspection. The assessment module110may be of any appropriate configuration and may be implemented in any appropriate manner. In one embodiment, the assessment module110includes at least one new production part sort logic112(e.g., logic configured to determine whether to accept or reject new production parts; incorporated/embodied by a non-transitory computer-readable storage medium), at least one in-service part sort logic114(e.g., logic configured to determine whether to accept or reject in-service parts; incorporated/embodied by a non-transitory computer-readable storage medium), along with one or more processors116of any appropriate type and which may be implemented in any appropriate manner. The assessment of the response of the part120to the input drive signals may entail comparing the response to a library118utilized by the resonance inspection tool100. This library118may be stored on a computer-readable storage medium of any appropriate type or types and in a non-transitory form (e.g., a non-transitory computer-readable storage medium), including without limitation by using one or more data storage devices of any appropriate type and disposed in any appropriate arrangement.

The library118of the resonance inspection tool100may include various types of resonance inspection results to allow the resonance inspection tool100to assess a part120. Generally, the resonance inspection results from the part120are compared with data in the library118from at least one other part that is the same as the part120in one or more respects (e.g., a part120in the form of a turbine blade will be compared to turbine blade data in the library118; a part120in the form of a turbine blade will not be compared with ball bearing data in the library118). Representative resonance inspection results are presented inFIG. 4, and are of a type that may be included in the library118. The three spectra122shown inFIG. 4represent the frequency response of a new production part120to a certain input frequency, and where this new production part120has been accepted by the resonance inspection tool100. Note how the three peaks128a,128b, and128cdiffer in at least one respect between the various spectra122, but yet the corresponding new production part120is acceptable in all three instances.

The three spectra124shown inFIG. 4represent the frequency response of an in-service part120to a certain input frequency, and where this in-service part120has been accepted by the resonance inspection tool100. Note how the three peaks128a,128b, and128cin the spectra124differ in at least one respect from the corresponding peaks128a,128b, and128cin the spectra122(again, associated with a new production part120).

The three spectra126shown inFIG. 4represent the frequency response of an in-service part120to a certain input frequency, and where this in-service part120has been rejected by the resonance inspection tool100. Note how the three peaks128a,128b, and128cin the spectra126differ in at least one respect from the corresponding peaks128a,128b, and128cin the spectra124(again, associated with an in-service part120that the resonance inspection tool100would accept). Generally, each of the peaks128a,128b, and128cin the spectra126has shifted to the left compared to the corresponding peaks128a,128b, and128cin the spectra122and124. Moreover, note the “compression” between the peaks128a,128bin the spectra126compared to the spectra122,124, as well as the “compression” between the peaks128b,128cin the spectra126compared to the spectra122,124.

One embodiment of a resonance inspection protocol that may be utilized by the resonance inspection tool100ofFIG. 3is presented inFIG. 5and is identified by reference numeral 130. Step132of the resonance inspection protocol130is directed to exciting a part120at a drive frequency (e.g. via a signal from the signal generator102that is input to the part120through the transducer104). The response of the part120is obtained or measured pursuant to step134(e.g., via one or more transducers106; via the transducer104in a single transducer configuration). It should be appreciated that steps132and134may be executed in at least partially overlapping relation (e.g., the frequency response of the part120could be obtained as a drive signal is being applied to the part120), although steps132and134could be sequentially executed as well.

The frequency response of the part120is assessed pursuant to step136of the resonance inspection protocol130. Step138of the protocol130is directed to determining if the frequency sweep is complete—whether each of the desired drive frequencies has been input to the part120. If not, the protocol130proceeds to step140, and which is directed to updating or changing the drive frequency to be input to the part120. Control is then returned to step132for repetition in accordance with the foregoing. Once the part120has been driven at each of the desired frequencies, the protocol130is terminated pursuant to step142.

Step136of the resonance inspection protocol130is again directed to assessing the response (e.g., frequency) of the part120(e.g., using the sort logic112or114and/or comparing the response of the part120to the library118of the resonance inspection tool100). This assessment may be undertaken at any appropriate time and in any appropriate manner. For instance, the assessment associated with step136could be undertaken while the part120continues to be driven by a signal at one or more frequencies. Another option is for the assessment provided by step136to be undertaken only after all drive signals have been input to the part120(step132), after the all frequency responses have been obtained (step134), or both.

A frequency response for a part, as described herein and including for purposes of step136of the resonance inspection protocol130ofFIG. 5, may actually be in the form of a plot or compilation of a collection of responses of a part-under-test (e.g., part120) at each frequency that may be used to drive the part-under-test. For instance, if a part-under-test is driven at frequency f1, the amplitude of the response of the part-under-test at this same frequency f1may be included in the noted plot at the frequency f1; if the part-under-test is driven at frequency f2, the amplitude of the response of the part-under-test at this same frequency f2may be included in the plot at the frequency f2; if the part-under-test is driven at frequency f3, the amplitude of the response of the part-under-test at this same frequency f3may be included in the plot at this frequency f3; and so forth. Any such plot is within the scope of a “frequency response” as set forth herein.

One embodiment of a sort protocol is presented inFIG. 6and is identified by reference numeral 150. The sort protocol150may be utilized by the in-service part sort logic114of the resonance inspection tool100shown inFIG. 3, and is configured for the assessment of in-service parts. Generally, the sort protocol150is directed to determining whether or not an in-service part is experiencing normal changes while in service. Stated another way, the sort protocol130may be characterized as being directed to determining whether an in-service part is aging normally or abnormally and via a resonance inspection. Each resonance inspection of an in-service part may be conducted while the in-service part remains in an installed state or condition (e.g., in situ) for purposes of the sort protocol150. Alternatively, each resonance inspection of an in-service part may be conducted with the in-service part being in an uninstalled state or condition (e.g., after having been removed from an assembly incorporating the same) for purposes of the sort protocol150.

A resonance inspection of a first in-service part (e.g., part120shown inFIG. 3) is conducted pursuant to step152of the sort protocol150ofFIG. 6(e.g., via execution of the resonance inspection protocol130ofFIG. 5). The frequency response of the first in-service part is compared with a resonance standard pursuant to step154. This “resonance standard” may be incorporated by the library118used by the resonance inspection tool100(FIG. 3) and/or may be utilized by the in-service part sort logic114, and in any case may characterize or define what should be a “normal change” for a predetermined in-service part (e.g., to determine whether the first in-service part is changing or aging in a normal manner or fashion). That is, the comparison of step154is undertaken for purposes of determining whether the first in-service part is changing normally or abnormally (step156). If the comparison with the resonance standard (step154) determines that the first in-service part is changing abnormally, the sort protocol150proceeds from step156to step160. A first in-service part that is changing abnormally may be rejected by the sort protocol150pursuant to step160(e.g., the first in-service part may be designated to be taken out of service). A first in-service part that is changing normally is accepted by the sort protocol150pursuant to step158(e.g., the first in-service part may be returned to service).

The resonance standard associated with step154may include actual and/or projected/predicted resonance inspection results. Moreover, these resonance inspection results may be from various points in time over the life cycle of a part (e.g., resonance inspection results when in the form of a new production part, resonance inspection results at or associated with 5,000 cycles of usage, resonance inspection results at or associated with 10,000 cycles of usage, resonance inspection results at or associated with 15,000 cycles of usage, and so forth). Step156of the sort protocol150may or may not take usage data (e.g., hours or cycles of operation) into account when assessing a particular in-service part. For instance, step156could be configured so that resonance inspection results from the in-service part being assessed via the sort protocol150would have to “match” data in the resonance standard having the same or comparable usage data (e.g., if the in-service part that was being assessed via the sort protocol150was at 10,000 cycles of usage, step156could be configured such that resonance inspection results from this in-service part would have to match data in the resonance standard that are also associated with 10,000 cycles of usage). Step156could also be configured so that resonance inspection results from the in-service part being assessed via the sort protocol150would only need to “match” data in the resonance standard, regardless of any associated usage data (e.g., step156could be configured to determine that a part at 10,000 cycles was changing normally, even though its resonance inspection results “matched” data in the resonance standard that was in fact associated with 20,000 cycles).

The resonance standard associated with step154of the sort protocol150ofFIG. 6may be of various forms. Representative resonance standards are shown inFIG. 6. The resonance standard for step154may be in the form of: 1) spectra from one or more other in-service parts (e.g., spectra from a resonance inspection previously conducted on one or more in-service parts other than that being inspected pursuant to the sort protocol150(box162a); 2) one or more spectra from a population of other in-service parts (box162b); 3) resonance inspection results predicted and/or derived via mathematical modeling (box162c); and 4) spectra obtained from accelerated life testing (box162d).

The resonance standard associated with step154of the sort protocol150could be in the form of any one or more of the type of spectra124shown inFIG. 4(e.g., box162a). If the resonance inspection results from the resonance inspection conducted pursuant to step152matched or complied with any of these spectra124in one or more respects, the in-service part could be accepted by step158of the sort protocol150.

The resonance standard used by step154of the sort protocol150may be based upon a population of in-service parts (box162b). This population of in-service parts does not need to include the first in-service part that is being assessed by the sort protocol150. The population of in-service parts may be viewed as a “peer group” for purposes of assessing the first in-service part via the sort protocol150(e.g., other parts manufactured in accordance with common specifications and/or that are functionally interchangeable with the first in-service part). For instance, the resonance standard may be in the form of spectra (e.g., spectra124fromFIG. 4) from each of a plurality of in-service parts that are within the population. If the comparison of step154determines that the resonance inspection results from the first in-service part (step152) match or comply with any of these spectra from the population in one or more respects, the first in-service part may be accepted pursuant to step158of the sort protocol150. The resonance standard associated with step154may also be in the form of an average of spectra from each of a plurality of in-service parts that are within the noted population. If the comparison of step154determines that the resonance inspection results (step152) match or comply with this spectral average from the population in one or more respects, the first in-service part may be accepted pursuant to step158of the sort protocol150.

The resonance standard associated with step154of the sort protocol150may also be provided by mathematical modeling (box162c). This mathematical modeling may be used to generate resonance inspection results for various times over the life of a part that is changing normally. If the comparison of step154determines that the resonance inspection results (step152) match or comply with any of these mathematically derived resonance inspection results in one or more respects, the first in-service part may be accepted pursuant to step158of the sort protocol150.

The resonance standard associated with step154of the sort protocol150may also be provided by accelerated life testing (box162d). Resonance inspection results may be acquired as a part undergoes accelerated life testing, and these resonance inspection results may be used by the resonance standard associated with step154. If the comparison of step154determines that the resonance inspection results (step152) match or comply with any of the resonance inspection results acquired during the accelerated life testing in one or more respects, the first in-service part may be accepted pursuant to step158of the sort protocol150.

One embodiment of a sort initialization protocol is presented inFIG. 7and is identified by reference numeral 170. The sort initialization protocol170may be utilized by and/or to configure the in-service part sort logic114of the resonance inspection tool100shown inFIG. 3, and is thereby associated with the assessment of in-service parts (e.g., logic configured to determine whether an in-service part should be rejected or accepted). A resonance inspection of a plurality of in-service parts (e.g., part120shown inFIG. 3) is conducted pursuant to step172of the sort initialization protocol170ofFIG. 7(e.g., via execution of the resonance inspection protocol130ofFIG. 5). A first subset of “normal” in-service parts (that underwent resonance inspection pursuant to step172) is defined pursuant to step174. A determination as to whether or not a given in-service part from step172is “normal” for purposes of step174may be undertaken in any appropriate manner, for instance using destructive testing, nondestructive testing, and/or a combination thereof.

A second subset of “abnormal” in-service parts (that underwent resonance inspection pursuant to step172) is defined pursuant to step176of the sort initialization protocol170. A determination as to whether or not a given in-service part from step172is “abnormal” for purposes of step176may be undertaken in any appropriate manner, for instance using destructive testing, nondestructive testing, or a combination thereof. In one embodiment, an in-service part that undergoes a resonance inspection pursuant to step172is characterized as normal (step174) or abnormal (step176) other than by the results of the resonance inspection associated with step172(e.g., via DT and/or NDT).

One or more destructive testing techniques may be used, one or more nondestructive testing techniques may be used, or both, in relation to each of steps174and176of the sort initialization protocol170ofFIG. 7. Representative nondestructive testing techniques that may be used in relation to each of steps174and176includes without limitation visual inspection, microscopy, magnetic particle, penetrant, eddy current, x-ray, computed tomography, flash thermography, ultrasound, sonic infra-red, phased array, or the like. Representative destructive testing techniques that may be used in relation to each of steps174and176includes without limitation fatigue testing, static testing, thermal testing, metalography, sectioning, ablation, chemical reduction, or the like.

Step178of the sort initialization protocol170ofFIG. 7is directed to defining a normal standard, while step180of the protocol170is directed to defining an abnormal standard. The normal standard associated with step178may be defined by one or more of the in-service parts associated with step174and may utilize results of the corresponding resonance inspection from step172(e.g., spectra of each in-service part within the first subset could be used by the normal standard; an average spectra from a plurality of in-service parts within the first subset could be used by the normal standard). Similarly, the abnormal standard associated with step180may be defined by one or more of the in-service parts associated with step176and may utilize results of the corresponding resonance inspection from step172(e.g., spectra of each in-service part within the second subset could be used by the abnormal standard; an average spectra from a plurality of in-service parts within the second subset could be used by the abnormal standard). Both the normal standard (178) and the abnormal standard (step180) may be stored (e.g., on a computer-readable storage medium) for use by the resonance inspection tool100through execution of step182of the sort initialization protocol170(e.g., included in the library118shown inFIG. 3).

Another embodiment of a sort protocol is presented inFIG. 8and is identified by reference numeral 190. The sort protocol190may be utilized by the in-service part sort logic114of the resonance inspection tool100shown inFIG. 3, and is configured for the assessment of in-service parts. The resonance inspection of an in-service part may be conducted while the in-service part remains in an installed state or condition (e.g., in situ) for purposes of the sort protocol190. Alternatively, the resonance inspection of an in-service part may be conducted with the in-service part being in an uninstalled state or condition (e.g., after having been removed from an assembly incorporating the same) for purposes of the sort protocol190.

A resonance inspection of a first in-service part (e.g., part120shown inFIG. 3) is conducted pursuant to step192of the sort protocol190ofFIG. 8(e.g., via execution of the resonance inspection protocol130ofFIG. 5). Results of the resonance inspection from step192may be compared with an abnormal standard (step194). The abnormal standard associated with steps194and196may be provided by the sort initialization protocol170ofFIG. 7. In any case, step196of the sort protocol190is directed to determining if resonance inspection results (step192) comply with the abnormal standard. The first in-service part is rejected if the resonance inspection results (step192) do in fact comply with the abnormal standard (step198).

Results of the resonance inspection may be compared with a normal standard (step200). Step202is directed to determining if resonance inspection results (step192) comply with the normal standard. The normal standard associated with steps200and202may be provided by the sort initialization protocol170ofFIG. 7. In any case, the first in-service part is accepted if resonance inspection results (step192) do in fact comply with the normal standard (step204). The first in-service part is rejected if resonance inspection results (step192) do not comply with the normal standard (step206) in the illustrated embodiment.

The protocol190may be configured to execute steps194and200in an order different from that shown inFIG. 8. Consider the case where the protocol190is configured to execute step200(comparison with a normal standard) before step194(comparison with an abnormal standard). If through execution of step202a determination is made that resonance inspection results (step192) do in fact comply with the normal standard, steps194and196could then be executed. If through execution of step196a determination is made that resonance inspection results (step192) do not comply with the abnormal standard, the protocol190could then proceed to the execution of step204(where the first in-service part is accepted by the resonance inspection tool100). However, if a determination was made that the resonance inspection results (step192) comply with the abnormal standard pursuant to step196, steps202and196of the protocol190would be providing inconsistent results. In this case, the sort protocol190could be configured to reject the first in-service part (step198)—even through resonance inspection results of the first in-service part were determined by the resonance inspection tool100to comply with the normal standard (step202).

The sort protocol190could also be configured to address a condition when resonance inspection results from step194do no match either the normal standard (step200) or the abnormal standard (step196). One option would be to associate the first in-service part with an unknown condition, and to thereafter further assess the first in-service part. The results of this further analysis could be used to update either the abnormal standard or the normal standard, depending upon whether the first in-service part was determined to be normal or abnormal.

One embodiment of a new production part sort update protocol is presented inFIG. 9and is identified by reference numeral 210. The sort update protocol210may be utilized by the new production part sort logic112of the resonance inspection tool100shown inFIG. 3. Generally, the sort update protocol210ofFIG. 9is configured to assess one or more in-service parts, and utilizes this assessment for purposes of updating the new production part sort logic112of the resonance inspection tool100. The resonance inspection of an in-service part may be conducted while the in-service part remains in an installed state or condition (e.g., in situ) for purposes of the sort update protocol210. Alternatively, the resonance inspection of an in-service part may be conducted with the in-service part being in an uninstalled state or condition (e.g., after having been removed from an assembly incorporating the same) for purposes of the sort update protocol210.

A resonance inspection of a first in-service part (e.g., part120shown inFIG. 3) is conducted pursuant to step212of the sort update protocol210ofFIG. 9(e.g., via execution of the resonance inspection protocol130ofFIG. 5). The first in-service part is assessed for any manufacturing defects pursuant to step214of the sort update protocol210. Any appropriate technique or combination of techniques may be used to determine whether or not the first in-service part has one or more manufacturing defects (e.g., via destructive testing and/or nondestructive testing). If no manufacturing defects are identified in the first in-service part, the sort update protocol proceeds from step216to step218, which terminates the protocol210. However, if at least one manufacturing defect is identified in the first in-service part (through execution of step214), the sort update protocol210proceeds from step216to step220. Pursuant to step220, data from the resonance inspection (step212) that corresponds with a given manufacturing defect is selected. This may be done in relation to each manufacturing defect that is identified in the first in-service part through execution of step214. The data from the resonance inspection that corresponds with a manufacturing defect may then be used to update the new production part sort logic112for the resonance inspection tool100ofFIG. 3. For instance, the library118of the resonance inspection tool100may be updated such that new production parts that originally would have been accepted by the resonance inspection tool100(prior to execution of the sort update protocol210) will now be rejected by the resonance inspection tool100if any such new production part includes a manufacturing defect that has been identified through execution of the sort update protocol210ofFIG. 9.

Another embodiment of a sort protocol is presented inFIG. 10and is identified by reference numeral 230. The sort protocol230may be utilized by the in-service part sort logic114of the resonance inspection tool100shown inFIG. 3, and is configured for the assessment of in-service parts. The resonance inspection of an in-service part may be conducted while the in-service part remains in an installed state or condition (e.g., in situ) for purposes of the sort protocol230. Alternatively, the resonance inspection of an in-service part may be conducted with the in-service part being in an uninstalled state or condition (e.g., after having been removed from an assembly incorporating the same) for purposes of the sort protocol230.

The sort protocol230is generally directed to monitoring in-service parts for an end-of-life (“EOL”) state or condition based upon resonance inspections of the in-service part that are conducted over time. Spaced-in-time resonance inspections of an in-service part may be conducted on any appropriate basis. For instance, an in-service part could be scheduled for a resonance inspection based upon time (e.g., on a calendar quarterly basis), based upon usage/usage data (e.g., hours of operation; cycles of operation), or the like. In one embodiment, an in-service part is scheduled for a resonance inspection based upon what may be characterized as a “cycle target.” Such a “cycle target” could be in the form of the in-service part being within a range of cycles, having been used for a minimum number of cycles, or the like.

A resonance inspection of a first in-service part (e.g., part120shown inFIG. 3) is conducted pursuant to step232of the sort protocol230ofFIG. 10(e.g., via execution of the resonance inspection protocol130ofFIG. 5). Resonance inspection data (e.g., the frequency response of the first in-service part) is acquired pursuant to step234. The acquisition of resonance inspection data from step234may be characterized as being part of the resonance inspection associated with step232.

Step236of the sort protocol230is directed to the monitoring first resonance inspection data. More specifically, step236is directed to monitoring first resonance inspection data for an occurrence of a first condition. This “first condition” may be in the form of a certain time-rate-of-change in the first resonance inspection data, and will be discussed in more detail below. In the event the first resonance inspection data does not exhibit a first condition, the sort protocol230proceeds from step238to step240. As the first condition was not identified in the first resonance inspection data, step240is directed to accepting the first in-service part. For instance, the protocol230may designate the first in-service part as being appropriate for further service. Another resonance inspection of the first in-service part may be conducted at a later time (e.g., after the expiration of a designated number of hours of operation or cycles of operation). As such, step240may return control to step232of the sort protocol230for repetition in accordance with the foregoing. Since a subsequent resonance inspection will typically be conducted at a later point in time, step240could also terminate the protocol230(e.g., an “end” step, and such that the protocol230would be re-run for each resonance inspection of the first in-service part).

In the event the sort protocol230identifies an occurrence of a first condition (e.g., via steps236and/or238), the protocol230proceeds from step238to step242. Step242is directed to associating an “end-of-life” or EOL condition or state with the first in-service part. This may entail designating the first in-service part for retirement such that the first in-service part is not returned to service.

The first resonance inspection data (step236) may be characterized as being part of and/or embodied by the resonance inspection data (step234). In one embodiment, the first resonance inspection data (step236) may be only part and/or may relate to only part of the resonance inspection data (step234). The first resonance inspection data (step236) may also be characterized as being based upon and/or derived from the resonance inspection data (step234).

The first resonance inspection data (step236) may be in the form of a frequency shift in the resonance inspection data (step234) over time. The first resonance inspection data (step236) may be in the form of: 1) a relative shift of at least one peak in the resonance inspection data acquired from multiple resonance inspections of the first in-service part (e.g., a shift of a first peak in the resonance inspection data relative to a second peak in the resonance inspection data); 2) an absolute shift of at least one peak in the resonance inspection data acquired from multiple resonance inspections of the first in-service part (e.g., a shift of a first peak in the resonance inspection data); 3) an appearance of at least one peak in the resonance inspection data acquired from multiple resonance inspections of the first in-service part; and 4) a disappearance of at least one peak in the resonance inspection data acquired from multiple resonance inspections of the first in-service part.

The “first condition” associated with step238may be characterized as being directed to a time-rate-of-change in resonance inspection results from resonance inspection to resonance inspection. That is, one or more parameters embodied by and/or relating to the resonance inspection results may be monitored from resonance inspection to resonance inspection to assess any corresponding change that may be occurring in relation to any such parameter. A certain change in any such parameter may be characterized as an occurrence of the first condition (step238).

FIG. 11illustrates representative first resonance inspection data that may be utilized by the sort protocol230ofFIG. 10. Plot250may be in the form of a frequency shift of a certain peak in the resonance inspection results from resonance inspection to resonance inspection (the “diamonds” being data points obtained from different resonance inspections over time). Plot252may be in the form of an “elongation” between a pair of peaks in the resonance inspection results from resonance inspection to resonance inspection (the “triangles” being data points obtained from different resonance inspections over time). “Elongation” means that the spacing between a pair of peaks in the resonance inspection results is being monitored for increases.

Another embodiment of a resonance inspection tool is illustrated inFIG. 12, is identified by reference numeral 100′, and is a variation of the resonance inspection tool100discussed above. Unless otherwise noted, the discussion of the resonance inspection tool100is equally applicable to the resonance inspection tool100′, including without limitation with regard to the acquisition of data on a part120. However, the resonance inspection tool100′ ofFIG. 12does include a modified assessment module110′ (e.g., incorporated/embodied by a non-transitory computer-readable storage medium). Principally, this assessment module110′ includes system/component part frequency assessment logic326. The assessment module110′ may also incorporate sort logic328to perform a resonance inspection on a part120(including having the sort logic328being configured in accordance with one or more of the protocols that were discussed in relation to the resonance inspection tool100).

A number of additional protocols for classifying a part will now be addressed, each of which may be utilized by the assessment module110′ of the resonance inspection tool100′, and each of which may be incorporated/embodied by a non-transitory computer-readable storage medium (e.g., each such protocol may be of a non-transitory form). Unless a resonance inspection is required by a particular one of these protocols, the resonance inspection tool100′ if course need not be configured to perform a resonance inspection, and as such it may be more generally referred to as a part evaluation system or tool100′ in conjunction with each of these protocols.

Any appropriate system (e.g., gearbox, transmission, jet engine) may be assessed using the system/component part frequency assessment logic326of the resonance inspection tool100′. Such a system may include one or more sub-systems or assemblies, one or more component parts (e.g., a gear, turbine blade), or any combination thereof. In any case, one or more moving component parts may be used by this system, one or more stationary parts may be used by this system, or both. A given component part of this type of system may move in any appropriate manner during at least part of the operation of the system at one or more steady-state operational frequencies (e.g., rotation, reciprocation, pivotal motion, translation). A “steady-state operational frequency” means where operation of the system is occurring on at least a substantially a constant basis (e.g., at a constant velocity; under non-accelerating conditions).

One embodiment of a part evaluation protocol is illustrated inFIG. 13, is identified by reference numeral 330, and may be utilized by the system/component part frequency assessment logic326for the resonance inspection tool100′. The part evaluation protocol330includes identifying a plurality of natural frequencies304for a system300that is operating at one or more steady-state operational frequencies308(step332). The system300could be operated at a single steady-state operational frequency308, or could be operated at any appropriate number of different steady-state operational frequencies308. Any appropriate number of natural frequencies304may be identified pursuant to step332of the part evaluation protocol330(e.g., two or more) and that occur at one or more steady-state operational frequencies308. The “natural frequency” in accordance with step332may be a natural frequency of the entirety of the system300, may be a natural frequency of at least one sub-system or assembly of the system300, may be the natural frequency of a particular component part of the system300, or any combination thereof.

Natural frequencies304of the system300may be may be acquired in any appropriate manner for purposes of step332of the part evaluation protocol332ofFIG. 13. Operation of the system300at one or more steady-state operational frequencies may be modeled (e.g., on a computer), and the natural frequencies304of the system304for step332of the protocol330may be acquired from this modeling (including in accordance with the modeling protocol390discussed below in relation toFIG. 18). Another option is to use functional testing of the system300to acquire the natural frequencies304of the system300for purposes of step332of the part evaluation protocol300. “Functional testing” includes actual operation of the system300(or at least a prototype of the system300). Computer modeling and functional testing may be used in combination to acquire the natural frequencies304of the system300for purposes of step332of the part evaluation protocol300.

The part evaluation protocol330further requires the acquisition of a first vibrational response312for a part-under-test310(step334). In this regard, the system300includes a first part302, and the part-under-test310for purposes of the part evaluation protocol300may be used as the first part302for the system300. This first part302may be stationary when installed and during operation of the system300, may move continually in any appropriate manner when installed and during operation of the system300, or may move in any appropriate manner at least at some point in time (e.g., intermittently; periodically; randomly) when installed and during operation of the system300. In any case, the first vibrational response312may be the frequency response of the part-under-test310, and may be acquired by the resonance inspection tool100′ in the manner discussed above with regard to the resonance inspection tool100(e.g., where a resonance inspection of the part-under-test310is undertaken with the resonance inspection tool100′). For instance, the first vibrational response312for the part-under-test310may be acquired by installing the part-under-test310within the resonance inspection tool100′ (e.g., at a time when the part-under-test310is not installed in the system300, or stated another way at a time when the part-under-test310is disassociated from the system300).

One or more resonance frequencies314are identified within the first vibrational response312pursuant to step336of the part evaluation protocol330ofFIG. 13. Step336may be executed by the resonance inspection tool100′. Any appropriate number of resonance frequencies314may be identified within the first vibrational response312, including each resonance frequency314within the first vibrational response312.

Each resonance frequency314within the first vibrational response312(part-under-test310) may be compared to a natural frequency threshold306of each natural frequency304(system300; step332) pursuant to step338of the part evaluation protocol330ofFIG. 13. This comparison may be undertaken by the resonance inspection tool100′. One or more of the natural frequency thresholds306for step338may be the same, one or more of the natural frequency thresholds306for step338may be different, or any combination thereof (e.g., the natural frequency threshold306need not be the same for each natural frequency304, although such could be the case).

The natural frequency threshold306for step338of the part evaluation protocol330ofFIG. 13may be of any appropriate magnitude. Each natural frequency threshold306may define a frequency range of any appropriate magnitude. Each natural frequency304may be disposed anywhere within its corresponding natural frequency threshold306. Although a given natural frequency304could be disposed in the middle of its corresponding natural frequency threshold306, such need not be the case.

The part-under-test310is classified (step342) based at least in part on the comparison from step338discussed above (e.g., the classification for step342may be based upon both the comparison of step338, and a supplemental resonance analysis that may be conducted pursuant to step340of the protocol330and that will be discussed in more detail below; the classification for purposes of step342may be based solely on the comparison of step338). For purposes of the part evaluation protocol330, the part-under-test310may be classified as either a compliant part (e.g., assigned a compliant part classification320) or a non-compliant part (e.g., assigned a non-compliant part classification322). Classification of the part-under-test310may be undertaken by the resonance inspection tool100′.

In the event that the part evaluation protocol330is configured without step340: 1) the protocol330may be configured such that the part-under-test310is assigned a compliant part classification320if each resonance frequency314(step336) for the part-under-test310is outside of the natural frequency threshold306(step338) of each natural frequency304for the system300(step332); and 2) the protocol330may be configured such that the part-under-test310is assigned a non-compliant part classification322if at least one resonance frequency314(step336) for the part-under-test310is within the natural frequency threshold306(step338) of at least one natural frequency304of the system300(step332).

The part evaluation protocol330ofFIG. 13may be used to assess parts of any kind, including without limitation original equipment (OEM) parts, parts manufacturer approval (PMA) parts, parts that are candidates for approval as a parts manufacturer (PMA) part, or any part that is not an OEM part. The part evaluation protocol330may be executed at any appropriate time in relation to a particular part-under-test310, including where the part-under-test310is a new production part as addressed above, after the part-under-test310has been in use as the first part302for the system300(e.g., exposed to operation of the system300), or both. One embodiment has a part being evaluated in accordance with the part evaluation protocol330prior to ever having been used in the system300(e.g., prior to the original/initial installation of the part (as the first part302) in the system300, and including where the part is a new production part), and thereafter being evaluated in accordance with the part evaluation protocol330one or more times after the part has been used in an operating system300(e.g., after the part has been exposed to operation of the system300—where the part-under-test310would then be in the form of an in-service part). One embodiment has a part being evaluated in accordance with the part evaluation protocol330prior to each time that the part is installed in the system300as a first part302, including prior to the first time that the part is installed in the system300as a first part302, as well as prior to each time that this same part is re-installed in the system300as a first part302(for instance, after the part has been removed from the system300for any purpose, including for a resonance inspection, for repair, for refurbishment, or any combination thereof).

One embodiment of a sort protocol is presented inFIG. 14, is identified by reference numeral 350, may be used by step340of the part evaluation protocol330ofFIG. 13, and may be utilized by the sort logic328for the resonance inspection tool100′ ofFIG. 12. The sort protocol350can also be used independently of the part evaluation protocol330. In any case, a frequency response is acquired for the part-under-test310pursuant to step352. This frequency response may be acquired pursuant to execution of a resonance inspection of the part-under-test310in accordance with the foregoing. The frequency response for step352of the sort protocol350may be in the form of the first vibrational response312for the part evaluation protocol330ofFIG. 13.

The frequency response (step352) may be compared to or tested against a sort324through execution of step354of the sort protocol350ofFIG. 14. The part-under-test310may be classified (step356) based at least in part on this testing against the sort324(step354). The part-under-test310may be assigned or designated a compliant part classification320or a non-compliant part classification322(step356).

The frequency response (step352) is tested against the sort324pursuant to step354. A “sort324”, as used herein, is at least generally in accordance with the discussion of a resonance standard presented above. A sort324may be characterized as an algorithm or a combination of algorithms that are used to determine if at least one characteristic (e.g., an attribute and/or a relationship), and more typically to determine if a plurality of characteristics, exist in relation to a certain frequency response. For instance, a sort324may be configured to require a peak of at least a certain amplitude at one or more frequencies in a frequency response, the lack of any peak of at least a certain amplitude throughout one or more frequency ranges of a frequency response, a predetermined relationship between one or more peaks in a frequency response (e.g., an amplitude ratio threshold), and the like. In any case and if a given frequency response is characterized as passing a sort324, this may mean that the corresponding part-under-test310includes the characteristic or combination of characteristics embodied or required by the sort324. Conversely and if a given frequency response is characterized as failing a sort324, this may mean that the corresponding part-under-test310fails to include one or more characteristics that are embodied or required by the sort324. Alternatively: 1) the phrase “passing a sort” may be equated with the sort324providing a compliant part classification sort result; and 2) the phrase “failing a sort” may be equated with the sort324providing a non-compliant part classification sort result.

In the case where the sort protocol350ofFIG. 14is being used independently of the part evaluation protocol330ofFIG. 13, the protocol350may be configured such that the part-under-test310is assigned a compliant part classification320(step356) if: 1) the frequency response (step352; e.g., the first vibrational response312) passes the sort324(step354) and where the sort324is configured to identify one or more predetermined characteristics of a compliant part; or 2) the frequency response (step352; e.g., the first vibrational response312) fails the sort324(step354) and where the sort324is configured to identify one or more predetermined characteristics of a non-compliant part. In the case where the sort protocol350ofFIG. 14is being used independently of the part evaluation protocol330ofFIG. 13, the protocol350may be configured such that the part-under-test310is assigned a non-compliant part classification322(step356) if: 1) the frequency response (step352; e.g., the first vibrational response312) passes the sort324(step354) and where the sort324is configured to identify one or more predetermined characteristics of a non-compliant part; or 2) the frequency response (step352; e.g., the first vibrational response312) fails the sort324(step354) and where the sort324is configured to identify one or more predetermined characteristics of a compliant part.

As noted, the sort protocol350ofFIG. 14may be used by step340of the part evaluation protocol330ofFIG. 13(although the sort protocol350could itself be used to assess a part-under-test310). In the case where the sort protocol350is used by step340of the part evaluation protocol330, and pursuant to the classification step342of the part evaluation protocol330, the protocol330may be configured such that the part-under-test310is assigned a compliant part classification320only if: 1) each resonance frequency314(step336) for the part-under-test310is outside of the natural frequency threshold306(step338) of each natural frequency304for the system300(step332); and 2) the frequency response (step352; e.g., the first vibrational response312) passes the sort324(step354) and where the sort324is configured to identify one or more predetermined characteristics of a compliant part (or where the frequency response fails the sort324and where the sort324is configured to identify one or more predetermined characteristics of a non-compliant part). In the case where the sort protocol350is used by step340of the part evaluation protocol330, and pursuant to the classification step342of the part evaluation protocol330, the protocol330may be configured such that the part-under-test310is assigned a non-compliant part classification322upon satisfaction of at least one of the following: 1) at least one resonance frequency314(step336) for the part-under-test310is within the natural frequency threshold306(step338) of at least one natural frequency304for the system300(step332); and 2) the frequency response (step352; e.g., the first vibrational response312) passes the sort324(step354) and where the sort324is configured to identify one or more predetermined characteristics of a non-compliant part (or where the frequency response fails the sort324and where the sort324is configured to identify one or more predetermined characteristics of a compliant part).

The sort324used by the sort protocol350ofFIG. 14may be based upon and/or developed from any appropriate data. For instance, the sort324may be based upon data acquired from the resonance inspection of one or more parts (including for the case where these parts were determined (on at least some basis) to be compliant (e.g., non-defective)). The sort324may be based upon a computer model of the first part302. The sort324may be based upon functional testing of the first part302(or at least functional testing of a prototype of the first part302). The sort324may be based upon data from two of more data sources, including any combination of the foregoing.

The sort protocol350ofFIG. 14may be used to assess any appropriate part-under-test310, such as a new production part (e.g., one that has not yet been installed in the system300as a first part302) or an in-service part (e.g., one that has been installed in the system300as a first part302, and where the system300as been operated such that the part has been exposed to operating conditions). In the case where the part-under-test310is an in-service part, the sort protocol350may be configured to determine if the part is aging normally or abnormally, and including in accordance with the foregoing.

Another embodiment of a sort protocol is presented inFIG. 15, is identified by reference numeral 360, may be used by step340of the part evaluation protocol330ofFIG. 13, and may be utilized by the sort logic328for the resonance inspection tool100′ ofFIG. 12. The sort protocol360can also be used independently of the part evaluation protocol330. In any case, a frequency response is acquired for the part-under-test310pursuant to step362. This frequency response may be acquired pursuant to execution of a resonance inspection on the part-under-test310in accordance with the foregoing. The frequency response for step362of the sort protocol360may be in the form of the first vibrational response312for the part evaluation protocol330ofFIG. 13.

The frequency response (step362) may be compared to at least one resonance standard368through execution of step364of the sort protocol360ofFIG. 15. The part-under-test310may be classified (step366) based at least in part on this comparison (step364). The part-under-test310may be assigned a compliant part classification320or a non-compliant part classification322(step366).

The resonance standard368for purposes of step364of the sort protocol360ofFIG. 15may be in accordance with the foregoing. There could be one or more resonance standards368for parts that are assigned a compliant part classification320(e.g., an accepted part; a non-defective part), there could be one or more resonance standards368for parts that are assigned a non-compliant part classification322(e.g., a rejected part; a defective part), or both for purposes of step364of the sort protocol360ofFIG. 15.

In the case where the sort protocol360ofFIG. 15is being used independently of the part evaluation protocol330ofFIG. 13, the protocol360may be configured such that the part-under-test310is assigned a compliant part classification320(step366) if: 1) the frequency response (step352; e.g., the first vibrational response312) complies with at least one resonance standard368that is used by the protocol360and that is associated with a compliant part (step364); and/or 2) if the frequency response (step352; e.g., the first vibrational response312) does not comply with any resonance standard368that is used by the protocol360and that is associated with a non-compliant part. In the case where the sort protocol360ofFIG. 15is being used independently of the part evaluation protocol330ofFIG. 13, the protocol350may be configured such that the part-under-test310is assigned a non-compliant part classification322(step366) if: 1) the frequency response (step352; e.g., the first vibrational response312) complies with at least one resonance standard368that is used by the protocol360and that is associated with a non-compliant part (step364); and/or 2) if the frequency response (step352; e.g., the first vibrational response312) fails to comply with at least one resonance standard368that is used by the protocol360and that is associated with a compliant part (step364).

As noted, the sort protocol360ofFIG. 15may be used by step340of the part evaluation protocol330ofFIG. 13(although the sort protocol360could itself be used to assess a part-under-test310). In the case where the sort protocol360is used by step340of the part evaluation protocol330, and pursuant to the classification step342of the part evaluation protocol330, the protocol330may be configured such that the part-under-test310is assigned a compliant part classification320only if: 1) each resonance frequency314(step336) for the part-under-test310is outside of the natural frequency threshold306(step338) of each natural frequency304for the system300(step332); and 2) the frequency response (step352; e.g., the first vibrational response312) complies with at least one resonance standard368that is used by the protocol360and that is associated with a compliant part (step364) (and/or where the frequency response does not comply with any resonance standard368that is used by the protocol360and that is associated with a non-compliant part). In the case where the sort protocol360is used by step340of the part evaluation protocol330, and pursuant to the classification step342of the part evaluation protocol330, the protocol330may be configured such that the part-under-test310is assigned a non-compliant part classification322upon satisfaction of at least one of the following: 1) at least one resonance frequency314(step336) for the part-under-test310is within the natural frequency threshold306(step338) of at least one natural frequency304for the system300(step332); and 2) the frequency response (step352; e.g., the first vibrational response312) complies with at least one resonance standard368that is used by the protocol360and that is associated with a non-compliant part (step364) (and/or where the frequency response fails to comply with at least one resonance standard368that is used by the protocol360and that is associated with a compliant part (step364)).

The resonance standard(s)368used by the sort protocol360ofFIG. 15may be based upon and/or developed from any appropriate data. For instance, each resonance standard368may be based upon data acquired from the resonance inspection of one or more parts, including for the case where these parts were determined (on at least some basis) to be compliant (e.g., non-defective) or to be non-compliant (e.g., defective). Each resonance standard368may be based upon a computer model of the first part302. Each resonance standard368may be based upon functional testing of the first part302(or at least functional testing of a prototype of the first part302). Each resonance standard368may be based upon data from two of more data sources, including any combination of the foregoing.

The sort protocol360ofFIG. 15may be used to assess any appropriate part-under-test310, such as a new production part (e.g., one that has not yet been installed in the system300as a first part302) or an in-service part (e.g., one that has been installed in the system300as a first part302, and where the system300as been operated such that the part has been exposed to operating conditions). In the case where the part-under-test310is an in-service part, the sort protocol360may be configured to determine if the part is aging normally or abnormally, and including in accordance with the foregoing.

Another embodiment of a sort protocol is presented inFIG. 16, is identified by reference numeral 370, may be used by step340of the part evaluation protocol330ofFIG. 13, and may be utilized by the sort logic328for the resonance inspection tool100′ ofFIG. 12.

The sort protocol370can also be used independently of the part evaluation protocol330. In any case, a frequency response is acquired for the part-under-test310pursuant to step374. This frequency response may be acquired pursuant to execution of a resonance inspection of the part-under-test310in accordance with the foregoing. The frequency response for step374of the sort protocol370may be in the form of the first vibrational response312for the part evaluation protocol330ofFIG. 13.

The frequency response (step374) may be compared to the frequency response of one or more compliant parts through execution of step376of the sort protocol370ofFIG. 16(e.g., the frequency response of a compliant part may be in accordance with the resonance standard368discussed above in relation to the sort protocol360ofFIG. 15). The frequency response of the part-under-test310and the frequency response of each compliant part used by the protocol370could be acquired through a resonance inspection in accordance with the foregoing (including where the part-under-test310and the compliant part(s) are exposed to the same drive frequencies or using the same frequency sweep). The part-under-test310may be classified (step378) based at least in part on this comparison (step376). The part-under-test310may be assigned a compliant part classification320or a non-compliant part classification322.

As noted, the sort protocol370ofFIG. 16may be used by step340of the part evaluation protocol330ofFIG. 13(although the sort protocol370could itself be used to assess a part-under-test310). In the case where the sort protocol370is used by step340of the part evaluation protocol330, and pursuant to the classification step342of the part evaluation protocol330, the protocol330may be configured such that the part-under-test310is assigned or designated a compliant part classification320only if: 1) each resonance frequency314(step336) for the part-under-test310is outside of the natural frequency threshold306(step338) of each natural frequency304for the system300(step332); and 2) the frequency response (step376; e.g., the first vibrational response312) complies with the frequency response of at least one compliant part that is used by the protocol370(step376). In the case where the sort protocol360is used by step340of the part evaluation protocol330, and pursuant to the classification step342of the part evaluation protocol330, the protocol330may be configured such that the part-under-test310is assigned a non-compliant part classification322upon satisfaction of at least one of the following: 1) at least one resonance frequency314(step336) for the part-under-test310is within the natural frequency threshold306(step338) of at least one natural frequency304for the system300(step332); and 2) the frequency response (step352; e.g., the first vibrational response312) fails to comply with the frequency response of each compliant part that is used by the protocol370(step376).

Another embodiment of a sort protocol is presented inFIG. 17, is identified by reference numeral 380, may be used by step340of the part evaluation protocol330ofFIG. 13, and may be utilized by the sort logic328for the resonance inspection tool100′ ofFIG. 12. A frequency response is acquired for the part-under-test310pursuant to step384. This frequency response may be acquired pursuant to execution of a resonance inspection on the part-under-test310in accordance with the foregoing. The frequency response for step384of the sort protocol380may be in the form of the first vibrational response312for the part evaluation protocol330ofFIG. 13.

The frequency response (step384) may be compared to one or more resonance frequency thresholds382through execution of step386of the sort protocol380ofFIG. 17. The resonance response of the part-under-test310may be acquired through a resonance inspection in accordance with the foregoing. In any case, the part-under-test310may be classified (step388) based at least in part on this comparison (step386). The part-under-test310may be assigned a compliant part classification320or a non-compliant part classification322.

The protocol380may be configured such that one or more resonance frequencies314in the frequency response (step384) are compared to one or more predetermined resonance frequency thresholds382(step386). One or more predetermined resonance frequency thresholds382may be stored in the memory of the resonance inspection tool100′ for use by the protocol380(e.g., within the library118). Each such resonance frequency threshold382may be defined in relation to a particular resonance frequency, and one or more predetermined characteristics of this particular resonance frequency (e.g., within +/−“x” of such a resonance frequency, with an amplitude of at least “y”). Each resonance frequency threshold382may be in the form of a certain frequency range, and furthermore may require a resonance frequency peak having an amplitude of at least a certain amount). That is, “complying” with a given resonance frequency threshold382means that there must be at least one resonance frequency314in the frequency response (step384) that is within a frequency range associated with each resonance frequency threshold382.

As noted, the sort protocol380ofFIG. 17may be used by step340of the part evaluation protocol330ofFIG. 13(although the sort protocol380could itself be used to assess a part-under-test310, as will be discussed below). In the case where the sort protocol380is used by step340of the part evaluation protocol330(FIG. 13), and pursuant to the classification step342of the part evaluation protocol330, the protocol330may be configured such that the part-under-test310is assigned or designated a compliant part classification320only if: 1) each resonance frequency314(step336) for the part-under-test310is outside of the natural frequency threshold306(step338) of each natural frequency304for the system300(step332); and 2) a separate resonance frequency314for the part-under-test310complies with each resonance frequency threshold382that is used by the protocol380(step386)—at least one resonance frequency314in the frequency response (step384) exists within the frequency range associated with each resonance frequency threshold382. In the case where the sort protocol380is used by step340of the part evaluation protocol330(FIG. 13), and pursuant to the classification step342of the part evaluation protocol330, the protocol330may be configured such that the part-under-test310is assigned a non-compliant part classification322upon satisfaction of at least one of the following: 1) at least one resonance frequency314(step336) for the part-under-test310is within the natural frequency threshold306(step338) of at least one natural frequency304for the system300(step332); and 2) a separate resonance frequency314for the part-under-test310fails to comply with each resonance frequency threshold382that is used by the protocol380(step386)—at least one resonance frequency threshold382is not satisfied by any resonance frequency314in the frequency response (step384) of the part-under-test310.

The sort protocol380ofFIG. 17may also be used independently of the part evaluation protocol330ofFIG. 13. The resonance frequency thresholds382for step386in this case may be based upon parts that have passed operational certification testing (an “operationally-certified part). Initially, parts that are exposed to such operational certification testing are parts having a design that has not yet been approved for production/end-use (e.g., the part design (including both an original design and any subsequent re-design) has not yet been approved by one or more relevant entities or authorities; a part design (including both an original design and any subsequent re-design) lacks the appropriate certification or certifications from one or more relevant entities or authorities). “Operational certification testing” as used herein means actual testing of a part in its end use configuration (e.g., the part being incorporated into a device, assembly, or system, where this device, assembly, or system is then operated in accordance with one or more standards that are at least based upon the end-use application(s)). “Operational certification testing”, as used herein, thereby encompasses “engine certification testing”—a process by which an engine manufacturer tests an engine (including all of its associated parts) and submits test data and other information (e.g., computations) on this engine to obtain a required certification from the relevant authority (e.g., the Federal Aviation Administration or FAA). “Operational certification testing” also thereby encompasses testing associated with obtaining Parts Manufacturer Approval—a process by which a third party replacement part is tested for use in another's engine, and where the third party submits test data and other information (e.g., computations) on this replacement part to obtain a required certification from the relevant authority (e.g., the FAA).

After operational certification testing of a given part has occurred (an operationally-tested part): 1) one or more a resonance inspections of this same operationally-tested part may be performed (e.g., in accordance with the resonance inspection protocol130ofFIG. 5), and the results of each such resonance inspection (e.g., the frequency response of the operationally-tested part) are retained; and 2) the same operationally-tested part is subjected to non-destructive testing, destructive testing, or both to determine if the operationally-tested part passed the operational certification testing. Obviously the resonance inspection(s) of the operationally-tested part must be done prior to any destructive testing of the operationally-tested part. There also may be circumstances where it may be desirable to perform the resonance inspection of the operationally-tested part prior to subjecting this part to non-destructive testing.

An operationally-certified resonance standard383(FIG. 17A) for use by the sort protocol380ofFIG. 17may be defined from the frequency response of one or more parts that have each passed the requisite operational certification testing (an operationally-certified part). Preferably the operationally-certified resonance standard383is defined from multiple operationally-certified parts, although it could be based upon a single operationally-certified part. In any case, this operationally-certified resonance standard383may be based upon resonance testing of a part that has completed operational certification testing (and is determined to have passed this operational certification testing), but prior to any further use of this very same part (e.g., the resonance testing may be done on a “new” operationally-certified part). The operationally-certified resonance standard383in this case may be characterized as being for assessing new production parts—a new production part resonance standard383. The operationally-certified resonance standard383could also be based upon resonance testing of an operationally-certified part, but where this resonance testing occurs after the part has been in service for some amount of time after having completed and passed operational certification testing (e.g., the resonance testing may be done on an “in-service” operationally-certified part). The operationally-certified resonance standard383in this case may be characterized as being for assessing in-service parts—an in-service resonance standard383. It should be appreciated that the same operationally-certified part could be used to define plurality of different resonance standards383which may collectively define at least part of the life cycle for the part (e.g., each resonance standard383being associated with a different time in the life cycle of the part).

In any case and referring toFIG. 17A, an operationally-certified resonance standard383may include one or more resonance frequency thresholds382as defined above. The operationally-certified resonance standard383ofFIG. 17Ais defined from four operationally-certified parts, whereFIG. 17Apresents the first vibrational or frequency response312for each such part. Any appropriate number of resonance frequency thresholds382may be used by an operationally-certified resonance standard383(five resonance frequency thresholds382a-382ebeing illustrated inFIG. 17A). Generally, a resonance frequency314of the first vibrational or frequency response312of each operationally-certified part may be grouped with a resonance frequency314of the other vibrational or frequency responses312to define a corresponding resonance frequency threshold382. Again, each resonance frequency threshold382may encompass a certain frequency range, and may require a resonance frequency314or resonance frequency peak of at least a certain amplitude within the corresponding frequency range.

An operationally-certified resonance standard383(FIG. 17A) may be used by the sort protocol380ofFIG. 17, more specifically by step386of the sort protocol380. The frequency response of the part-under-test310(step384) may be compared to the operationally-certified resonance standard383. If the part-under-test310complies with the operationally-certified resonance standard383(if the frequency response of the part-under-test310has a separate resonance frequency314that complies with each resonance frequency threshold382of the resonance standard383(e.g., where at least one resonance frequency314exists within the frequency range associated with each resonance frequency threshold382)), the part-under-test310may be assigned to a compliant part classification320(step388). If the part-under-test310fails to comply with the operationally-certified resonance standard383(e.g., if the frequency response of the part-under-test310does not have a resonance frequency314that complies with at least one of the resonance frequency thresholds382of the standard383—a resonance frequency314does not exist within the frequency range associated with at least one of the frequency thresholds382), the part-under-test310may be assigned to a non-compliant part classification322(step388).

Modeling may be used in relation to one or more aspects of the part evaluation protocol330ofFIG. 13and as noted above. Modeling may be used to identify the natural frequencies304for the system300for purposes of step332of the part evaluation protocol330. The frequency response of the part-under-test310(step334) may be compared to a computer model of the first part302for purposes of step340of the part evaluation protocol330, for instance where the sort324for step354of the sort protocol350(FIG. 14) is based at least in part on a computer model of the first part302, or where one or more resonance standards368for step364of the sort protocol360(FIG. 15) are based at least in part on a computer model of the first part302.

One embodiment of a modeling protocol is presented inFIG. 18, is identified by reference numeral 390, may be stored on a non-transitory computer-readable storage medium, and may be executed by an appropriate computer. A frequency response is acquired for the part-under-test310pursuant to step392. This frequency response may be acquired pursuant to execution of a resonance inspection on the part-under-test310in accordance with the foregoing, or otherwise in the same manner as has been described herein with regard to conducting a resonance inspection. The frequency response for step392of the modeling protocol390may be in the form of the first vibrational response312for the part evaluation protocol330ofFIG. 13.

A first transfer function404is applied to the frequency response (step392) pursuant to execution of step394of the modeling protocol390. This first transfer function404defines the vibrational response of the part-under-test310(step392) in free space, and which also may be referred to as a first transformed frequency response406. The first transformed frequency response406(step396) may be characterized as a transformation or translation of the frequency response (step392) for when the part-under-test310is in free space. That is and in the case of the resonance inspection tool100′ ofFIG. 12, the part-under-test310is contacted by the resonance inspection tool100′ (e.g., by one or more transducers104,106). This contact between the resonance inspection tool100′ and the part-under-test310will affect the frequency response of the part-under-test310. The first transfer function404of step394may be characterized as predicting what the vibrational response of the part-under-test310would be if the resonance inspection tool100′ did not have to contact the part-under-test310for purposes of a resonance inspection.

Step396of the modeling protocol390is directed to comparing the above-noted first transformed frequency response406to a modeled frequency response410. A “modeled frequency response410” for purposes of step396of the modeling protocol390is a frequency response of the first part302of the system300that is predicted by a computer model408of the first part302. Again and as noted above, the part-under-test310may be used as a first part302within the system300. The computer model408for the first part302may be defined in any appropriate manner and may be used for any appropriate purpose, including for predicting the frequency response of the first part302.

The computer model408of the first part302for the system300may be updated pursuant to the execution of step398of the modeling protocol390ofFIG. 18, for instance based upon the first transformed frequency response406. That is, data on the actual frequency response of the part-under-test310(after the application of the first transfer function404) may be used to adjust the computer model408of the first part302for the system300(e.g., so that the computer model408of the first part302more closely approximates the part-under-test310at least on a vibrational response or frequency response basis). In any case, a second transfer function412may then be applied to the modeled frequency response410for the computer model408of the first part302(after any update of this computer model408pursuant to step398) pursuant to execution of step400of the modeling protocol390.

The second transfer function412associated with step400of the modeling protocol390predicts the frequency response of the first part302when installed within an operational system300(e.g., where the first part302may be contacted by one or more other parts of the system300), including where the system300is operated in accordance with at least one steady-state operational frequency308(e.g., for purposes of step332of the part evaluation protocol330ofFIG. 13). Updating of the computer model408for the first part302of the system300(step398) may be viewed as updating a computer model414of the overall system300—step400of the modeling protocol390may be used to update the computer model414of the overall system300.

The updated computer model414of the system300(step402of the modeling protocol390ofFIG. 18) may be used to identify one or more natural frequencies304of the system300for purposes of step332of the part evaluation protocol330ofFIG. 13(and furthermore may then be used to set each natural frequency threshold306that may be used by the part evaluation protocol330). The updated computer model408of the first part302(step398of the modeling protocol390ofFIG. 18) may be used for any appropriate purpose. The updated computer model408of the first part302(step398of the modeling protocol390) could also be used as a data source for: 1) the sort324for the sort protocol350ofFIG. 14(including when used by step340of the part evaluation protocol330ofFIG. 13), and/or 2) a resonance standard368for the sort protocol360ofFIG. 15(including when used by step340of the part evaluation protocol330ofFIG. 13). The updated computer model408of the first part302could also be used in establishing the resonance frequency thresholds382for the sort protocol380ofFIG. 17, for the case where the sort protocol380is used by step340of the part evaluation protocol330ofFIG. 13.

The part evaluation protocol330ofFIG. 13(including the sort protocol350ofFIG. 14; the sort protocol360ofFIG. 15; the sort protocol370ofFIG. 16; the sort protocol380ofFIG. 17) may be used in any appropriate manner and for any appropriate purpose. A part that has been used as a first part302in the system300may be repaired and/or refurbished at one or more times. Such a repaired and/or refurbished part may be assessed through execution of the part evaluation protocol330and/or one or more of the sort protocols350,360,370, and/or380(including at a time when the part has been removed from the system300).

A redesign of a part may be assessed through execution of the part evaluation protocol330and/or one or more of the sort protocols350,360,370, and/or380. Consider the case where: 1) a first part-under-test310is in accordance with a first design; and 2) a different second part-under-test310is in accordance with a second design. In one embodiment, the first and second designs are each in accordance with a common product specifications standard, and each of the first and second parts-under-test310in this example may be assessed through execution of the part evaluation protocol330and/or one or more of the sort protocols350,360,370, and/or380. In another embodiment, the first design is in accordance with a first product specifications standard, the second design is in accordance with a second product specifications standard (which includes one or more updates of the first products specifications standard), and each of the first and second parts-under-test310in this example may be assessed through execution of the part evaluation protocol330and/or one or more of the sort protocols350,360,370, and/or380.

One or more aspects of manufacturing may be assessed through execution of the part evaluation protocol330and/or one or more of the sort protocols350,360,370, and/or380. Manufacturing specifications may apply to the first part302for the system300. Consider the case where: 1) a first part-under-test310is manufactured in accordance with a first manufacturing protocol that is within a manufacturing specifications standard; and 2) a different second part-under-test310is some time thereafter manufactured in accordance with a second manufacturing protocol that is also within this same manufacturing specifications standard (e.g., the second manufacturing protocol may be an update of the first manufacturing protocol). In this case, each of the first and second parts-under-test310may be assessed through execution of the part evaluation protocol330and/or one or more of the sort protocols350,360,370, and/or380. The part evaluation protocol330and/or one or more of the sort protocols350,360,370, and/or380may each then be characterized as evaluating changes in a manufacturing protocol, but where the “original” manufacturing protocol and the “updated” manufacturing protocol are each still in accordance with a predetermine manufacturing specifications standard.

Updated manufacturing specifications may be assessed through execution of the part evaluation protocol330and/or one or more of the sort protocols350,360,370, and/or380. Consider the case where: 1) a first part-under-test310is manufactured in accordance with a first manufacturing specifications standard; and 2) a different second part-under-test310is some time thereafter manufactured in accordance with a second manufacturing specifications standard (i.e., the second manufacturing specifications standard differs in at least one respect from the first manufacturing specifications standard). In this case, each of the first and second parts-under-test310may be assessed through execution of the part evaluation protocol330and/or one or more of the sort protocols350,360,370, and/or380. The part evaluation protocol330and/or one or more of the sort protocols350,360,370, and/or380may each then be characterized as evaluating the “update” of the manufacturing specifications standard.

Each of the protocols330,350,360,370, and380may be used to assign a part-under-test310to a compliant part classification320. Each of the protocols330,350,360,370, and380may be used to assign a part-under-test310to a non-compliant part classification322. In the case of the sort protocols350,360,370, and380, the “compliant part classification320” may be equated with an accepted part, with a non-defective part, or both. Conversely and for the sort protocols350,360,370, and380, the “non-compliant part classification322” may be equated with a rejected part, with a part having one or more defects, or both.