bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Overload Plastic Zone Size on Stress Corrosion Crack Growth Behavior of a Low Alloy Steel in 3.0% NaCl Solution
Authors: Putatunda SK , Venugopal V
Published: February 2009

An investigation was carried out to examine the influence of overload plastic zone size on stress corrosion crack growth behavior for a low alloy steel. The investigation also examines the influence of initial stress intensity factor on stress corrosion crack growth behavior. Compact tension specimens with TL orientation prepared from SAE 4140 steel in the hardened and tempered condition were used. Two pertinent environments were chosen: deionized water at room temperature (23°C) and 3.0% NaCl solution at room temperature (23°C).

The specimens were initially precracked in fatigue and loaded to different levels of stress intensity factors. Crack growth behavior of these specimens was studied by keeping them submerged in deionized water and 3.0% NaCl solution to establish a base line. To examine the influence of overload plastic zone size on stress corrosion crack growth behavior, the precracked specimens were overloaded to various load levels (i.e., 5, 10, 25, and 50% more than their initial stress intensity level [Ki]) and then unloaded. The crack growth behavior of these specimens was then monitored in a similar fashion after reloading to the original initial stress intensity level. The influence of initial stress intensity level on the incubation period for the growth of the crack and on the stress corrosion crack growth rate was also examined.

The results of the present investigation demonstrate that the incubation period for the growth of stress corrosion cracking increases with an increase in overload plastic zone size. The crack growth rate at a constant initial stress intensity level was found to be lower in salt water solution than in deionized water. The incubation period for the growth of stress corrosion cracking was found to decrease with an increase in initial stress intensity level.

Once the crack has grown beyond the introduced overload plastic zone, the crack growth rate was found to resume its normal rate. However, for the similar overload plastic zone size, the reduction of the effective crack growth rate was found to be greater in deionized water than in salt solution. This reduction in effective crack growth rate in overloaded specimens can be attributed to the presence of residual compressive stresses in the crack tip region in overloaded specimens.
Use of Cantilever Specimens to Determine Microcreep Properties
Authors: Santner JS
Published: February 2009

Cantilever beams were employed to determine the microyield strength (MYS) and the microstress relaxation (MSR) behavior of composites for stable member applications. Cantilever beams were designed and the compliance determined using resistance strain gages. Two different composites were tested: 2124-T6/30% SiC and Al-2.5Mg/20% SiC. A 2124-T6/30%SiC composite, previously tested under axial compression, was used to compare its data with the results of this study using bend specimens. The latter material was chosen because of its lower yield strength and modulus. The cantilever beam geometry is a significantly easier configuration to test and obtain over one per million resolution in strain than equivalent axial compression specimens. This allows cost-effective development of microcreep data using readily available standard mechanical test equipment. Additional test development work may permit this technique to be developed into an ASTM standard. It also offers the opportunity to measure the elastic, plastic, and anelastic strain components to develop engineering materials with improved MYS and MSR properties.
A Method for Uniform Shear Stress-Strain Analysis of Adhesives
Authors: Wycherley GW , Mestan SA , Grabovac I
Published: February 2009

The adaptation of the Iosipescu test as a method for determination of the stress and strain to failure and the shear modulus of adhesives under uniform shear conditions is described. The design and performance of a number of special purpose instruments and jigs to facilitate sample preparation, bond line thickness measurement, and shear displacement determinations are also described. Representative shear stress-strain curves of a nylon-epoxy film adhesive are presented.
Fatigue Behavior of a Cold-Rolled SAE Grade 945X HSLA Steel
Authors: Yu MT , DuQuesnay DL , Topper TH
Published: February 2009

A SAE Grade 945X HSLA steel was cold rolled to 30% and 61% thickness reductions. Monotonic tensile tests, smooth and notched specimen fatigue tests, and crack propagation tests were performed. The effect of loading direction was examined. As a general rule, cold rolling increased strength and decreased ductility. The strength was higher and the ductility was lower in the direction transverse to the rolling direction than in the longitudinal or rolling direction. The increase in smooth specimen fatigue strength was not as great as the increase in monotonic strength due to significant cyclic softening of the cold rolled metals. The notched fatigue strength was only slightly increased by cold rolling, since two opposing factors (the smooth specimen fatigue strength and notch sensitivity) were increased by cold rolling. The crack propagation rate and the threshold stress intensity were not significantly affected by cold rolling. All strength parameters of the SAE 945X HSLA steel, both hot rolled and cold rolled, were higher than those of a SAE 1010 plain carbon steel previously investigated.
Plastic Strain Ratio (r) for Sheet Metal: Effect of Gage Length and Width Measurement Locations Using Reduced Section Specimens
Authors: Taylor JS , Scherrer DK
Published: February 2009

Recent advances in computer-controlled testing technology have resulted in the capability of determining r-values during routine tension testing. During axial straining, there are differences in width reduction over the length of the reduced parallel section due to shoulder constraint. Because of these changes in width reduction, the magnitude of the calculated r-value is dependent upon the gage length and width measurement location. The use of a 50 mm (2 in.) or less longitudinal strain sensor with a single transverse center width sensor does not presently comply with ASTM Test for Plastic Strain Ratio r for Sheet Metal (E 517). Yet the data from this work demonstrate that excellent r-value results can be obtained using a 50 mm (2 in.) longitudinal sensor with a single center transverse sensor while still maintaining a 57 mm (2¼ in.) reduced parallel section which complies with ASTM Tests and Definitions for Mechanical Testing of Steel Products (A 370) and Tension Testing of Metallic Materials (E 8).
Crevice Corrosion Testing in Natural Seawater: Significance and Use of Multiple Crevice Assemblies
Authors: Kain RM
Published: February 2009

Multiple crevice assemblies (MCAs) have been used for over a dozen years to assess the crevice corrosion resistance of stainless-type alloys in seawater and other chloride-containing environments. This paper provides a review of the technique's development, modification, and present usage and discusses its limitations. Results of comparative round-robin testing and other seawater crevice corrosion studies provide perspectives on reproducibility. Insight from established corrosion mechanisms and modelling help to explain variability for some materials. Several examples of alloy rankings and beneficial effects of alloy composition determined by MCA tests are discussed.
A Rapid Method for Measurement of Rolling Contact Fatigue Limit of Case-Hardened Gear Materials
Authors: Jiang B , Shao E
Published: February 2009

A rapid method for measurement of the rolling contact fatigue limit of case-hardened gear materials was developed according to Miner theory [1] by step loading. For performing the fatigue test by the rapid method, only one specimen is needed and no more than a few hours of testing are required. With respect to the conventional method it can increase testing efficiency by a hundred times. The relative error of the resulting fatigue limit is less than 5%.
Dynamic Strain-Aging and Neutron Irradiation Effects on Mechanical and Fracture Properties of A533B Class 1 PV Steel and 2.25Cr-1Mo Steel
Authors: Mahmood ST , Al-Otaibi KM , Jung YH , Linga Murty K
Published: February 2009

Effects of dynamic strain-aging (DSA) on upper-shelf ductility of A533B Class1 pressure vessel (PV) and 2.25Cr-1Mo steels are discussed along with those of low fluence (5 × 1021 n/m2) fast (>1 MeV) neutron irradiation on mechanical and fracture properties of the PV steel. Mechanical and fracture property data were generated using tensile and three-point bend tests. Tests were performed on as-received and irradiated A533B steel and as-received 2.25Cr-1Mo steel as a function of test temperature and applied strain-rate in the range of 300 to 623 K and 6.7 × 10−5 s−1 to 1 × 10−2 s−1, respectively. The tests were aimed at characterizing the effects of DSA on the mechanical and fracture behaviors of these steels as well as investigating the synergistic effects of DSA, and radiation defects.

Reduced ductility and fracture initiation energy were observed in both steels in the temperature and strain-rate ranges where DSA occurred. This range of temperatures corresponded to the uppershelf regime for PV steel. The strain-aging characteristics were very similar to those observed in mild steels albeit the load fluctuations and effects are relatively small. At some temperatures and strainrates, irradiation suppressed DSA resulting in improved mechanical and fracture characteristics at these relatively low fluences. Surface morphology studies performed on the fractured specimens of Cr-Mo steel revealed significant changes in the usual ductile fracture appearance at temperatures where DSA was noted.
A K1 Calibration for a Modified Single Edge Notched Tension Specimen
Authors: Kirk MT , Sanford RJ
Published: February 2009

Using global and boundary collocation techniques, a single edge notched tension (SE(T)) specimen, modified by introduction of a semi-circular cutout in front of the crack, was developed and characterized. This specimen was found to produce fixed-grip K1 values two times greater than is possible with a conventional SE(T) specimen of the same size. This new specimen could be used to investigate upper transition crack arrest phenomena with smaller specimens and testing machine capacities than have been possible previously.
Force Plate for Corrugated Container Vibration Tests
Authors: Urbanik TJ
Published: February 2009

A stack of corrugated containers subjected to over-the-road vibrations behaves like a distributed spring-mass system. Severe stack vibrations can crush the bottom container, fatigue the product cushioning, and damage the product. Laboratory tests were conducted to characterize the spring-mass system response to vibration by using a force plate combined with a single accelerometer. By using the force plate, only two data acquisition channels are needed to measure the driving acceleration and response force beneath a container stack. The acceleration and force data become input to a model that reduces the stack to an equivalent single-degree-of-freedom system and identifies its properties. The merits of alternate stacking patterns and interior packaging can then be quantified in terms of their generalized mass, stiffness, and damping and the effect of these properties on the stack response. Cushioning vibration characteristics are determined for flexible product-container interactions. Container designs can be improved based on understanding the physics of transportation vibrations.
Fracture of Defect Foam Core Sandwich Beams
Authors: Groth HL , Zenkert D
Published: February 2009

In the manufacturing of foam core sandwich structures, butt-joints are frequently used within the core. However, inherent flaws may be developed in such joints. Hence areas of stress concentration, such as sharp corners, will exist that may have critical influence on structural behavior. The same type of sharp corners appears in a standard shear test (ASTM C 273) used for determination of shear properties of core materials.

The present paper deals with the analysis of flawed butt-joints in sandwich beams. The analysis is based on a fracture mechanics approach. It is assumed that sharp bi-material corners will be present between the core and face material in the sandwich beam which can be compared with the interface between the core material and the edge plates in the shear test specimen. Such sharp corners develop singular stress fields which are used together with a suitable fracture criterion to predict structural failure in sandwich beams. The results from the standard shear tests for core materials are used to evaluate fracture mechanics parameters. These parameters are used for the prediction of fracture loads of sandwich beams with simulated flaws.
Damage Tolerance Analysis of Multiple-Site Cracks Emanating from Hole Array
Authors: Nishimura T , Noguchi Y , Uchimoto T
Published: February 2009

A versatile method is discussed for estimating stress intensity factors for multiple-site cracks emanating from a row of fastener holes located perpendicular to the loading direction in a finite plate. The stress intensity factor is determined by multiplying geometry factors based upon existing solutions for simpler geometries (cracks at hole, plate width, neighboring holes, and other cracks). The accuracy of the stress intensity factor is checked by comparing the solutions obtained from other literature and those calculated by the finite element method. Finally, the proposed stress intensity solution is used to estimate fatigue crack propagation for multiple-site cracks emanating from five fastener holes in a finite width plate. Through this estimate, the proposed method is assessed by comparing predictions with test results.
Fatigue Crack Characterization by Ultrasonic Inspection
Authors: Rehbein DK , Thompson RB , Buck O
Published: February 2009

The ultrasonic interrogation of components for the detection and sizing of defects has advantages over other techniques in that surface as well as subsurface defects can be probed. However, the phenomenon of crack closure or crack surface contact can reduce the detectability of a crack and lead to erroneous crack sizing. The significance of crack closure is twofold: (1) It is important for the interpretation of fatigue data, in particular as affected by the stress ratio, by spike overloads/underloads, and by threshold effects. (2) It affects the detection probability of fatigue cracks, which influences strongly the capability for accurate life prediction. In the present paper, the interaction of ultrasound with fatigue cracks will be discussed with primary emphasis on the first objective.

The experimental configuration of our ultrasonic measurements is such that a fatigue crack is illuminated by a longitudinal wave incident perpendicular to the crack face and focussed in the plane of the crack. The longitudinal wave is partially transmitted by the closure zone and picked up by another focussed receiver transducer. By changing the angular orientation of this receiver, longitudinal or transverse polarized waves diffracted in the closure zone can be detected. By spectral analysis, translation of the sample with respect to the detection system and rotation of the receiver, one can monitor the frequency, spatial, and angular dependence of the crack transmissivity. These data are composed with a “spring” model, which replaces the topological description of the closure region, providing the spatial distribution of the average diameter, d, and average separation, C, of the contacts.

From this contact topology and the “flow pressure” (three times the ultimate tensile strength) of the material we deduced the residual stress field in the wake of the crack. These results agree well with X-ray diffraction measurements. Furthermore, we estimated the “shielding” stress intensity factor using these results for a number of fatigue cracks grown under a variety of loading conditions. If shielding is taken into account, the effects of load excursions on fatigue crack propagation can be estimated with reasonable accuracy.
Bore Inspection and Life Evaluation of Vintage Steam Turbine/Generator Rotors
Authors: Jhansale HR , McCann DR
Published: February 2009

This paper describes the approach and methodology used for bore inspection and life evaluation/extension of vintage steam turbine spindles and generator rotors for continued service. The non-destructive inspections, including visual, magnetic particle, and ultrasonic, together with flaw sizing procedures, are described. Life evaluation and extension approaches include conventional and finite element stress and thermal analyses, state-of-the-art material evaluation studies, and fatigue, creep, and fracture mechanics based techniques. Based on the experience of these ongoing studies on over 250 spindles and rotors (manufactured by Allis-Chalmers, General Electric, and Westinghouse), two essential recommendations are made. Firstly, it is best to evaluate each vintage spindle/rotor on a case-by-case basis instead of a historical and generic basis. Secondly, most of the vintage spindles/rotors can continue to be used safely and with a high degree of reliability with proper periodic inspections and evaluations and life extension measures as needed.
Handbook of Environmental Fate and Exposure Data for Organic Chemicals
Authors: Mones E
Published: February 2009

Volume I in this series deals with organic chemicals that fall into the category of large production volumes and priority pollutants. This reference work is well organized and easy to follow. It provides not only data but a brief discussion of particular topics such as log octanol/water partition coefficient, biodegradation, abiotic degradation, and bioconcentration. The author's description of each of these topics extremely helpful, especially to those using these types of data for the first time. However, all terms used in these sections are not defined. While there are some minor differences in some physical data between this and other reference books, the author supplies the reference with the data, allowing one to easily find the original source. It is also important to realize that, while this is a good reference book, for fate and exposure data, no aquatic toxicity data are listed.
Evaluation of Variability in Resilient Modulus Test Results (ASTM D 4123)
Authors: Brown ER , Foo KY
Published: February 2009

Samples of asphalt mixture were evaluated in the laboratory under various conditions to evaluate the repeatability of the resilient modulus test and the effect of stress on the measured resilient modulus. Some samples were prepared in the laboratory, others were obtained from in-place pavements that had been subjected to traffic. The independent variables included stress, test temperature, and maximum aggregate size.

Tests were repeated a number of times, and the data were analyzed by Statistical Analysis System (SAS) to investigate their repeatability. This study quantified the repeatability of the ASTM D 4123 resilient modulus test as a function of stiffness. The repeatability of ASTM D 4123 is low. A significant increase in the number of samples or number of measurements is required to improve the repeatability. Tests conducted at different stresses showed the resilient modulus to be stress sensitive. This indicated that stress should be specified in the test procedure. A correction factor was established for stresses differing from the recommended stress (15% of tensile strength) for test temperatures of 25 and 40°C.
Deformation of Aluminum Alloy under Cyclic Creep Loadings
Authors: Gong ZL , Hsu TR
Published: February 2009

Cyclic creep tests were conducted on an aluminum alloy at 160 and 200°C. Measured results indicated that mechanical load cycling with long dwell periods can produce significant creep acceleration. Such creep acceleration not only resulted in the increasing of minimum strain rate at subsequent loading cycles, but also reduced the creep rupture life of the material. Microstructure examinations by TEM and SEM were carried out to study microstructural damages under monotonic and cyclic loadings. Results indicated that remobilization of dislocation and damage enhancement during stress cycling were chiefly responsible for creep acceleration.
A Thick Adherend, Instrumented Double-Cantilever-Beam Specimen for Measuring Debonding of Adhesive Joints
Authors: Crosley PB , Ripling EJ
Published: February 2009

An inexpensive test method for evaluating the debond resistance of adhesive joints is described. A double-cantilever-beam specimen is used, and a strain gage is mounted on the unbonded portion of one adherend. When a fixed displacement is applied to the end of the specimen, the strain gage output along with the specimen compliance and the amount of fixed displacement at the end of the specimen are used to calculate the crack length, a, and the sustainable crack driving force, G, at the time the gage is read.
Charpy Impact Tests Near Absolute Zero
Authors: Tobler RL , Reed RP , Hwang IS , Morra MM , Ballinger RG , Nakajima H , Shimamoto S
Published: February 2009

We review Charpy impact testing at extreme cryogenic temperatures, especially at liquid helium temperature (4 K), considering methods of testing and calibration, thermal behavior during the various stages of testing, and correlations between Charpy absorbed energy and quantitative toughness parameters. Because of the very low specific heats of metals near absolute zero, any surface condensation of gases, convective or conductive heat transfer, or plastic deformation during a test will cause the specimen temperature to rise rapidly. Consequently, valid impact tests of alloys at 4 K can not be performed according to the procedure outlined in ASTM Methods E 23-88. During Charpy tests, the temperature of austenitic steel specimens, initially at or near 4 K, may in fact rise outside the cryogenic regime. Fracture does not occur at the intended temperature, but at an uncontrolled temperature, since materials with different work hardening rates heat differently. In view of the temperature rise variability and scatter in measurements and property correlations, we conclude that it is not possible to accurately estimate the 4 K fracture toughness of ductile steels, or rank them properly, using Charpy tests.
Improved Wide Range Expressions for Displacements and Inverse Displacements for Standard Fracture Toughness Specimens
Authors: Kapp JA
Published: February 2009

Wide range expressions (interpolating polynomials) for displacements for standard ASTM fracture testing specimens have been developed. The strategy was to fit displacements as a function of crack length for all the specimens using a similar form of nondimensional displacement. Different forms appear in different ASTM standards for the same or similar specimens. The criterion used to establish the degree of polynomial fit and number of significant figures for the coefficients of the polynomial was for the polynomial to agree with the best available numerical displacement solutions to within 1% or better. Once the polynomials for displacement as a function of crack length were developed, inverted forms of the specific interpolating polynomials were obtained to determine relative crack length (a/W) as a function of displacement. Since the inverted polynomial will be used in tandem with the interpolating polynomial, the inverted polynomial was fit to the interpolating polynomial and not the numerical solution for displacement. Three forms of nondimensional displacements were used to invert the interpolating polynomials. The criterion used to establish the degree of polynomial and the number of significant figures of the coefficients of the polynomial was for the predicted relative crack length to agree with the actual relative crack depth to within 0.0005W. A sensitivity analysis was performed to suggest which form of interpolating polynomial should be used for standards.
Computer-Aided Homogeneity Testing of Proposed Metal and Metal Alloy Reference Materials
Authors: Hurwitz JK
Published: February 2009

In an analytical laboratory, reference materials are used for several purposes, including the calibration of analytical instruments, periodic standardization of these instruments, and verification that the standardization is correct. Reference materials are also used to confirm that an analysis is performed with optimum precision and is not biased, and to determine the presence and effects of interferences. All of these applications require that proposed reference materials be evaluated for homogeneity. To this end, specimens are cut at regular intervals from bars selected for evaluation and identified accordingly. Across the entire cross section of each specimen, a flat surface is prepared as specified by the analytical method. The specimens are analyzed in random order by optical emission spectrometry, once at the center of the specimen and twice as close to the edge of the specimen as possible. If X-ray emission (fluorescent) spectrometry is used, two analyses are performed with a fresh specimen preparation before each analysis. Statistical analyses are performed on the values obtained for each element to determine whether there are significant differences in composition between center and edge or among specimens. This procedure has been used successfully for ten years to evaluate proposed reference materials prior to certification.
A Novel Specimen Geometry for Double Shear Creep Experiments
Authors: Kim H-K , Mohamed FA , Earthman JC
Published: February 2009

A new specimen geometry has been developed to reduce the stress concentrations at the ends of the gage section in double shear creep specimens. The purpose of the geometry is to reduce the tendency for crack formation at the gage section ends when testing creep brittle materials. A comparison of creep data indicates that the sharp corners at the ends of the gage sections of the conventional geometry has a negligible effect on the steady-state creep behavior. The results also suggest that, when a nonuniform gage section is used, the stresses redistribute during primary creep such that steady-state flow is driven by the mean shear stress over the entire gage section.
Design and Analysis of Jaw Crusher Gouging Abrasion Tests
Authors: Sare IR , Constantine AG
Published: February 2009

ASTM Standard Practice G 81-83 describes a laboratory procedure for determining the relative gouging abrasion resistance of materials in a jaw crusher. The authors have found a number of problems associated with the test procedure, particularly in respect of its inefficiency, the fact that it yields biased estimates of the wear parameter, and its lack of facility for assessing the significance of differences between test results. An alternative methodology for conducting the tests and for analyzing the data is proposed, and it is shown, by example, how substantially more information can be obtained from tests results than has hitherto been demonstrated.
Specimen Size Requirements for Fracture Toughness Testing in the Transition Region
Authors: Anderson TL , Dodds RH
Published: February 2009

The article utilizes plane strain elastic-plastic finite element analysis and a local criterion for cleavage fracture to establish specimen size requirements for the ductile-brittle transition region. Critical J and CTOD values, relative to the small-scale yielding value, were predicted as a function of specimen size, strain hardening exponent, and a/W. These analyses predict an increase in the apparent toughness with decreasing specimen size due to a loss in crack tip constraint; this effect is particularly pronounced in shallow notched specimens and low hardening materials. For deeply notched bend and compact specimens, the following size requirement must be met for critical J values for cleavage to be size independent: b,B,a>200JcσY where b is ligament length, B is thickness, a is crack length, and σγ is flow stress. This criterion is eight times more severe than the size requirements in ASTM E 813-87, but it is less stringent than the requirements of ASTM E 399-83. In order for a CTOD value to be nearly size independent, it must be less than 1/300 times the relevant specimen dimensions.

The constraint loss in shallow notched specimens is usually far too rapid to obtain J-controlled cleavage fracture, but the analyses presented in this article provide a means for correcting fracture toughness data for constraint loss. Predictions of the effect of a/W on toughness in the transition region agree favorably with experimental data.

Future work will consider the effects of specimen thickness and ductile tearing on transition region toughness.
Plastic η and γ Factors for Compact Tension Specimen inJ-Integral Estimation
Authors: Hu JM , Albrecht P
Published: February 2009

The empirical expressions for the plastic η and γ factors adopted by ASTM in the standard test methods for Jlc and J-R curve testing (E 813 and E 1152) were determined from the results of experimental work. This note proposes instead expressions of ηp and γp that are derived from a limit load solution. The results show that over the range of crack lengths recommended for testing in the ASTM standard test methods, a/W = 0.5 to 0.75, the proposed ηp value is 5.11 to 1.42% greater than the ASTM value, and the proposed γp value is 12.93 to 5.82% greater.
Pulse Current Automatic Electro-Optical Characterization of the Laser Diode
Authors: Oyedokun ZO
Published: February 2009

An automated pulse current testing of the laser diode is presented. Built around an accurate and fast rise time pulse generator and a minicomputer, it has been used to test several laser diodes to extract characteristics such as threshold current and thermal resistance. The computer-controlled pulse generator offers multivariable control of output pulse. Control and data acquisition algorithms were developed in a low level language, MACRO11, to enhance speed and resource utilization, and in FORTRAN, which facilitated the man/machine interface or manware. Continuous wave and pulse test results are compared to illustrate the heating effects.
Prediction of the Strength of Ceramic Tubular Components: Part II—Experimental Verification
Authors: Shelleman DL , Jadaan OM , Conway JC , Mecholsky JJ
Published: February 2009

The strength distribution of reaction-bonded silicon carbide tubes that failed by internal pressurization was predicted from strength distributions obtained from simple laboratory test specimens at room temperature. The strength distributions of flexure bars, C-rings tested in tension, C-rings tested in compression, diametrally compressed O-rings, and internally pressurized short tubes were compared with the strength distribution of internally pressurized long tubes. The methodology involved application of Weibull statistics using elasticity theory to define the stress distributions in the simple specimens. The flexural specimens did not yield acceptable results, since they were ground before testing, thereby altering their flaw population in comparison with the processing-induced flaw populations of the tubular specimens. However, the short tube internal pressure test, the C-ring tested in tension, and the diametrally compressed O-ring test configurations yielded accurate strength predictions of full-scale tubular components, since these specimens more accurately represent the strength-limiting flaw population in the long tubes.
Accuracy of a Volume Fraction Measurement Using Areal Image Analysis
Authors: Shi D , Winslow D
Published: February 2009

The method of interval estimation is used to determine the accuracy of a volume fraction measurement obtained from an areal image analysis of a series of images. The accuracy is found to depend upon the average number of objects found in each section and the number of sections that are analyzed. The method can be applied to completed measurements on a set of two-dimensional sections to estimate the error in the result. Or, the method can be used before making any measurements to select the number of sections and the size of each section for a desired accuracy.
Nonintrusive Test for Argon Gas Content in Windows: Feasibility Study
Authors: Latta BM , Bogan L , Wagner GS
Published: February 2009

The objective was to find a nonintrusive technique for determining the gas content of an insulated glass window unit. During this study, first measurements of the electric breakdown field for air-argon mixtures were obtained. The breakdown field does not depend strongly on whether the electrodes are plain window glass or glass with low emissivity coatings, nor does it depend on the glass electrode spacing. Our reported strong variation of the breakdown field with admixtures of air to the argon gas suggests that this approach could provide an inexpensive nonintrusive gas analysis for insulated glass window units with an ultimate precision of 0.1% on the argon content.
Shear Strength of a Ductile Material from Torsion of Solid Cylinders
Authors: Lyon RE
Published: February 2009

The shear strengths of two ductile epoxies are obtained from solid cylinder torsion using a data reduction scheme. The results are in quantitative agreement with shear data from torsion of thin-walled tubes of the same materials, particularly with regard to the coincidence of the peak yield stress and strain. The described technique is useful for characterizing ductile material behavior in shear using a simple, solid cylinder specimen.
The Structural Ceramics Database: Data Acquisition Format for Monolithic Ceramics
Authors: Munro RG , Begley EF
Published: February 2009

The Structural Ceramics Database (SCD) is being developed to provide a user-friendly, computerized database of materials properties for advanced ceramics. The acquisition and the maintenance of adequate and comprehensive data are two of the critical concerns that must be addressed in establishing a state of the art system. This paper describes the basic SCD format used for data on monolithic ceramics. This format prescribes a comprehensive means for tabulating, annotating, and crediting data. The experience gained in developing this format for the SCD is discussed in the context of the issues confronting ASTM Committee E-49 on Computerization of Materials Property Data.
Theoretical Comparison of Error in KIc Values Determined by Different Testing Methods of Ceramics
Authors: Martins CS , Steen M , Rosa LG
Published: February 2009

Experimental errors in measuring the values of the different variables included in the formulae for KIc evaluation can affect the accuracy of fracture toughness results. In this work, the effect of error propagation, leading to the final error in the KIc value, is analyzed in terms of type of testing method and specimen geometry.

A review of eight different specimen geometries and procedures for fracture toughness testing of ceramics is given. The analysis was carried out through a FORTRAN 77 program specially developed for this purpose. The computer program takes into account the allowable errors that are associated with each type of recommended experimental procedure or common practice. Results obtained on hot-pressed silicon nitride (HP Si3N4) are presented as an example, but the conclusions can be extended to other engineering ceramics.
Procedure to Evaluate Openings in Children's Products for Head Entrapment Hazards
Authors: Deppa SW
Published: February 2009

Children have strangled when their heads became entrapped in structural openings of children's products. To analyze these accidents, we applied human factors principles of anthropometry, childhood development, perception, behavior, and biomechanics. Children under 5 years of age became entrapped either head first, feet first, or neck first. Four product characteristics contributed to accidents: product function, product weight/size, opening location, and opening configuration.

From this analysis, we developed a standard procedure for evaluating product openings. This procedure describes how to develop test fixtures to simulate the smallest and largest users at risk. This work can assist, and has assisted, product designers, manufacturers, and the U.S. Consumer Product Safety Commission in reducing head entrapment in product openings. For example, this procedure was used to develop provisions in ASTM voluntary standards for baby gates and enclosures, bunk beds, and playground equipment.
Laboratory Testing of River Gravel Used in Arrester Beds
Authors: Al-Qadi IL , Rivera-Ortiz LA
Published: February 2009

The objective of this study was to investigate the engineering properties of a river gravel. The engineering properties studied included shear strength, volume change, failure strain, and modulus of elasticity. The triaxial compressive strength of the river gravel was used in a developed model to obtain the stopping distance of a runaway truck in an arrester bed.

Static and dynamic triaxial compression tests were performed using a specially constructed triaxial cell on specimens 22.9 cm (9 in.) in diameter and 48.3 cm (19 in.) in height. Specially designed damping equipment was employed to perform the dynamic testing. The test specimens were subjected to different confining pressures.

The results of the study not only provide data on strength, relative volume change, failure strain, and modulus of elasticity but also on the relationship between these properties and influencing factors such as relative density, confining pressure, and loading rate. The material parameters of the river gravel were applied successfully in a mathematical model developed to predict the stopping distance of a run-away truck in an arrester bed.
Warm Precracking at 295 K and Its Effects on the 4-K Toughness of Austenitic Steels
Authors: Tobler RL , Shimada M
Published: February 2009

Experiments show that some austenitic steels at extreme cryogenic temperatures are toughened by warm prestress. We demonstrate this for Fe-17Cr-3Ni-13Mn-0.33N steel specimens that were warm precracked at 295 K and then fractured in liquid helium at 4 K where failure occurs by slip-plane cracking. On the other hand, Fe-13Cr-5Ni-22Mn-0.21N steel with higher toughness and a ductile fracture mechanism at 4 K was not affected by similar warm precracking. Austenitic and ferritic steel behaviors are compared, and precracking procedures for 4-K fracture tests are discussed.
Electrical Resistance Measurements on Type 304 Stainless Steel with Different Degrees of Sensitization
Authors: Kain V , Chouthai SS , Gadiyar HS
Published: February 2009

Most of the test methods commonly used to evaluate the susceptibility of austenitic stainless steels to intergranular attack are qualitative and destructive in nature. Practice A of ASTM Standard A 262 and the EPR tests are nondestructive but are less discriminating for higher degrees of sensitization. Because the sensitized material contains chromium-rich carbides at grain boundaries and chromium depletion zones at and adjacent to the grain boundaries compared with uniform structure in the solution annealed material, there is a need for a nondestructive test method using electrical resistance, eddy current, ultrasonic testing, or magnetic susceptibility. Testing methods based on eddy currents and ultrasonics are reported to be insensitive to the degree of sensitization. In this study an attempt is made to measure the electrical resistance for Type 304 stainless steel (SS) with various degrees of sensitization. The results indicated no correlation between the electrical resistance measurements and the degree of sensitization for Type 304 SS.
Energy Stored in a Specimen under Fatigue Limit Loading Conditions
Authors: Kaleta J , Blotny R , Harig H
Published: February 2009

This paper presents results of measuring the energy stored in a specimen made from Ck 35 carbon steel loaded with an alternating one-directional stress whose value is equal to the fatigue limit. The energy stored in the specimen was determined in an indirect way as the difference between the mechanical energy expended in the specimen and the energy released into the surroundings as heat. The proposed technique is a modified version of the dynamic hysteresis loop method. The energy released as heat was measured with an electric modelling method.

It was found that the energy stored during one cycle in a specimen loaded with a stress equal to the fatigue limit was larger than zero (i.e., with Nf→ ∝, the stored energy value theoretically also tends to infinity). To make the theory of the experiment compatible with the fundamental assumption stating that the amount of energy needed to cause fracture is constant irrespective of loading conditions, it is necessary to introduce a rheological function accounting for all reversible processes occurring in a material under cyclic loading.
Analysis of the Size Effect in Low-Load Hardness Testing of Metals
Authors: Atkinson M
Published: February 2009

Recent accounts of Vickers hardness tests in which the variation of hardness values with indentation size was suppressed by lubrication are re-examined to elucidate the nature of the size effect. It is shown that a simple constant error in either the measured indentation size or the force actually exerted would not explain the effect. A good description of the effect is obtained by reference to an indentation-size-dependent load error which is sensitive to both friction conditions and the plastic properties of the test material.
The Effect of Handling on the Compression Strength of Corrugated Fiberboard Containers
Authors: Singh SP , Crofts B , Burgess G
Published: February 2009

The ability of a corrugated fiberboard box to protect its contents is related to its compression strength. The corrugated container industry has been manufacturing corrugated fiberboard according to bursting strength and basis weight specifications. These specifications do not accurately reflect the ability of a box to meet performance requirements in the distribution environment. This study investigates the effect of package weight and the handling environment on the reduction in compression strength of corrugated containers. The mean compression strength and corresponding deflection values for three box sizes were evaluated as a function of package weight and drop height after handling. The compression strength decreased as the package weights increased and as the drop heights increased. The mean edge crush, flat crush, and bursting strength values were unchanged as the test conditions became more severe.
Understanding Impact Testing of Pallet Nails and Staples
Authors: Loferski JR , Stern EG
Published: February 2009

The assembly of wooden pallets, at a rate of more than 500 million units per year by more than 2500 American manufacturers, is mostly accomplished with nails and staples. The performance and useful life of these pallets are significantly influenced by the ability of these fasteners to resist relatively high impact forces during pallet use. Only a single testing device, described in ASTM Standard F 680, is available to provide the information on the impact resistance of these pallet fasteners. The accuracy, precision, and repeatability of the test data as well as the usefulness of this testing device are described by data on two types of pallet nails, obtained by single and multiple operators of this device. Among the conclusions advanced are that the mean test data are representative of the fastener performance characteristics and are repeatable and accurate if the testing device is used properly.
Theory and Practice of Force Measurement
Authors: Doebelin EO
Published: February 2009

The senior author, A. Bray, has been with the Institute of Metrology “G. Colonetti” in Turin, Italy, for many years, having established the first nucleus of the institute, which is today the Force Measurement Section. His colleagues G. Barbato and R. Levi are associated also with Politecnico di Torino. Reflective of the authors' experience, the major focus of the book is on high accuracy force measurement and calibration in standards laboratories. This relatively narrow focus limits the range of readership to which the book is addressed, but allows a high technical level in the treatment of those topics which are covered. Of the eight chapters, only the fifth, “Force-Measuring Devices,” would be of prime interest to the more general force-measurement community. The entire book, however, is of uniformly high quality and fills an important gap in the measurement literature.
An Introduction to the Design and Behavior of Bolted Joints
Authors: Link RE
Published: February 2009

Although the title of this book includes the word “introduction”, the treatment of the subject is extensive and complete. The material goes well beyond the coverage of bolted joint design received in a typical undergraduate machine design course. The easy-to-read text begins with the fundamentals of bolt strength, deformation, and material selection and proceeds to cover the topics of preload, torque, and stretch control. The emphasis is on practical considerations for the efficient design of joints, including cost, ease of assembly, inspection, and disassembly. This second, revised edition has expanded the coverage of corrosion, fatigue, gaskets, and ultrasonic measurement of bolt strain. Also included are discussions of the failure modes and mechanisms of bolted joints. Case histories from industry are presented throughout the text to illustrate key points. Many up-to-date references are presented at the end of each chapter to allow the reader to pursue individual topics further, if desired. The text contains several appendices with useful tables and formulas for quick reference. The author has broad experience in the subject area from many years as a consultant to the power generation and nuclear industry, active participation on society working groups such as ASME and PVRC, as well as the presentation of numerous seminars on the topic. This book would serve as a valuable desk reference for engineers concerned with the design and performance of bolted joints.
Evaluation of Rating Numbers for Atmospheric Corrosion Resistance of Weathering Steel
Authors: Albrecht P , Lee H
Published: February 2009

The term weathering steel describes a high-strength low-alloy composition consisting of a carbon steel base to which about 2% of alloying elements is added for corrosion resistance. These additions may consist of elements such as phosphorus, silicon, nickel, chromium, and copper within the limits prescribed in ASTM specifications A 242 and A 588.

Ideally and boldly exposed coupons of weathering steels corrode at low rates in atmospheric exposure tests. Therefore producers have recommended their use in bare, exposed steel structures.

The present study evaluates the atmospheric corrosion resistance of weathering steel specimens that are ideally and boldly exposed by ASTM Specification G 50.
In Situ Ultrasonic Examination of the Intense Pulsed Neutron Source (IPNS) Enriched Uranium Target Assembly
Authors: Bohringer DE , Kupperman DS , Bailey JL , Knox AE
Published: February 2009

The Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory is one of the nation's largest and most powerful sources of pulsed neutron beams for the study of atomic and molecular structures in solids and liquids. Due to large grains, preferred crystal orientation, and high neutron flux levels, irradiation growth of the enriched uranium target is a major factor in limiting the useful lifetime of the target assembly. Since predicting growth is difficult, in situ ultrasonic pulse-echo techniques are being used to periodically monitor the growth of the target assembly. Several tests have confirmed that irradiation growth of the target can be tracked and measured to an accuracy of 100 μm.
Inherently Conducting Polymers
Authors: Burnell G
Published: February 2009

The feasibility of electrically conducting polymers was explored theoretically in the 1960's but has been the subject of serious research only over the past decade or so. Dr. Aldissi's book reviews the progress of this research and describes the current state of the art. Various aspects of the subject are covered such as synthesis, properties, and applications, with the author adopting a mainly descriptive style.