Patent Description:
Mechanical components are typically used in various devices, such as internal combustion engines, gas turbine engines, motors, compressors, pumps, and the like. In gas turbine engines, mechanical components may include shafts, rotor blades, stator vanes, couplings, disks, and so on. During operation of such devices (e.g., the gas turbine engine), mechanical components are usually subjected to high mechanical and thermal loads. Further, the mechanical components are subjected to loads that impose a substantially steady force as well as a high-frequency alternating force (i.e., a time-varying force) during their operation. Therefore, it is important to evaluate or test a mechanical integrity and a durability of such mechanical components to determine a service life and a strength of these components.

Service representative conditions are required to be imposed on such mechanical components for testing their mechanical integrity. Such conditions may include the substantially steady force (e.g., a higher magnitude steady force) as well as the high-frequency alternating force (e.g., a lower magnitude alternating force). Various testing devices are currently available to impose such conditions on the mechanical components. Some testing devices utilize a hydraulic actuation system for applying the high magnitude steady force on the mechanical component to be tested. However, the hydraulic actuation system may not be suitable for imposing the high frequency alternating force on the mechanical component to be tested.

Some testing devices use a piezo-electric actuation system. The piezo-electric actuation system typically includes a piezo-electric actuator that converts electrical energy into mechanical displacement based on piezo-electric effect, or vice versa. The piezo-electric actuation system may be suitable for imposing the high frequency alternating force on the mechanical component. However, the piezo-electric actuator of the piezo electric actuation system may characteristically provide only small mechanical displacements for testing of the mechanical component. For instance, the piezo-electric actuation system may be suitable for cases where the mechanical component is required to be tested only for small alternating displacements. However, the piezo-electric actuation system may be unsuitable for applying a constant force having a large magnitude on the mechanical component.

Hence, a system for testing the integrity of mechanical components is required which overcomes the above-mentioned problems.

According to a first aspect, there is provided a system for testing at least one test piece. The system includes a pressure vessel. The pressure vessel includes a first chamber receiving a first fluid at a first pressure. The pressure vessel further includes a second chamber fluidly separated from the first chamber and receiving a second fluid. The pressure vessel further includes an actuating membrane fluidly separating the first chamber from the second chamber. The actuating membrane is configured to apply a second pressure on the second fluid within the second chamber in response to the application of the first pressure by the first fluid on the actuating membrane. The system further includes a test vessel including an internal chamber disposed in fluid communication with the second chamber and at least one test wall defining at least one boundary of the internal chamber. The at least one test wall is coupled to the at least one test piece. The internal chamber is configured to receive the second fluid at the second pressure. The at least one test wall is configured to apply a first force on the at least one test piece in response to the application of the second pressure by the second fluid on the at least one test wall. The system further includes an actuator engaged with the actuating membrane and configured to apply a time-varying force on the actuating membrane while the first pressure is being applied by the first fluid on the actuating membrane. The at least one test wall is further configured to apply a second force on the at least one test piece in addition to the first force in response to the application of the time-varying force by the actuator on the actuating membrane. The second force is time-varying and is different from the first force.

For testing the at least one test piece, the at least one test wall of the system may apply the first force as well as the second force on the at least one test piece. As the first force is applied in response to the application of the second pressure by the second fluid on the at least one test wall, the first force may be a steady force (e.g., a hydraulic force). The first force may provide a large steady force required for testing the at least one test piece.

The at least one test wall is configured to apply the second force on the at least one test piece in response to the application of the time-varying force by the actuator on the actuating membrane. As the second force is applied in response to the application of the time-varying force, the second force may be an alternating force required for testing the at least one test piece. Thus, the at least one test wall may be configured to apply the steady force (i.e., the first force) as well as the alternating force (i.e., the second force) on the at least one test piece for testing the at least one test piece. Hence, the system of the present disclosure may be configured to apply the alternating force in addition to the steady force on the at least one test piece for testing the at least one test piece.

Generally, in real time operations involving the use of the at least one test piece, the at least one test piece may be subjected to various loads generated by steady forces as well as alternating forces (i.e., time-varying forces). Such forces may correspond to service representative conditions of the at least one test piece. The system of the present disclosure may enable the application of the steady force and the alternating force on the at least one test piece. Thus, the system may be used for testing a durability and a mechanical integrity of the at least one test piece as the system can replicate the service representative conditions of the at least one test piece.

As compared to conventional techniques for testing the mechanical integrity of a test piece by applying only a hydraulic force, the system of the present disclosure may utilize a single setup for applying both the steady force (i.e., the first force) as well as the alternating force (i.e., the second force). In other words, the system uses the single setup for generating and imposing the service representative conditions on the at least one test piece. Thus, the system of the present disclosure may be able to accurately determine the durability and the mechanical integrity of the at least one test piece.

Further, by imposing the service representative conditions on the at least one test piece, a service life of the at least one test piece may be determined. This may further help in predicting a time for next inspection of the at least one test piece after the at least one test piece is put into service.

In some embodiments, the actuator includes a mass coupled to the actuating membrane. The actuator further includes an electromagnetic actuation device disposed proximal to the mass and configured to apply a time-varying actuating force on the mass, such that the mass oscillates relative to the pressure vessel to apply the time-varying force on the actuating membrane. The electromagnetic actuation device may include a magnetic field assembly and a coil winding. The electromagnetic actuation device uses a flow of current to oscillate the mass relative to the pressure vessel. Therefore, the electromagnetic actuation device is configured to apply the time-varying force on the actuating membrane. The time-varying force on the actuating membrane further leads to application of the second force on the at least one test piece required for testing the mechanical integrity of the at least one test piece.

In some embodiments, the actuator further includes a spring coupling the mass to the actuating membrane. By using the spring to couple the mass to the actuating membrane, the time-varying force is applied on the actuating membrane as a result of the oscillation of the mass.

In some embodiments, the spring includes a mechanical spring. Use of the mechanical spring may allow generation of the time-varying force on the actuating membrane.

In some embodiments, the spring includes a spring membrane disposed in the first chamber and an enclosed fluid disposed between the spring membrane and the actuating membrane. The spring membrane may be coupled to the mass. Use of the spring membrane and the enclosed fluid may allow generation of the time-varying force on the actuating membrane.

In some embodiments, the electromagnetic actuation device is further configured to apply the time-varying actuating force on the mass at a predetermined frequency. The predetermined frequency is equal to a natural frequency of a combination of the mass and the spring. As the predetermined frequency is equal to the natural frequency of the combination of the mass and the spring, the mass and the spring may oscillate at resonance. As a result, small oscillations of the mass may transform into a greater value of the time-varying force applied on the actuating membrane along with large displacements of the actuating membrane. As compared to a conventional piezo electric actuation system for testing the mechanical integrity of a test piece, the actuator of the proposed system may apply the alternating force (i.e., the second force) on the at least one test piece with small displacements as well as large displacements of the actuating membrane and/or the at least one test piece. The service representative conditions imposed on the at least one test piece may include small displacements as well as large displacements of the at least one test piece.

In some embodiments, the electromagnetic actuation device is a direct current linear actuator. Use of the direct current linear actuator may enhance an application of the time-varying actuating force on the mass.

In some embodiments, the first fluid is a gas, and the second fluid is a hydraulic fluid. Thus, the internal chamber of the test vessel may be hydraulically coupled with the second chamber of the pressure vessel. The hydraulic fluid may provide a stiff coupling between the test vessel and the second chamber as little energy is stored and released (due to incompressibility of the hydraulic fluid) as a pressure of the hydraulic fluid changes. As the second fluid is the hydraulic fluid, the at least one test wall is configured to apply a hydraulic force (i.e., the first force) on the at least one test piece in response to the application of the second pressure by the hydraulic fluid on the at least one test wall.

In some embodiments, the test vessel further includes an enclosing wall at least partially defining the internal chamber. The at least one test wall includes an elastic disc having a central portion and a circumferential portion fixedly coupled to the enclosing wall. The central portion is coupled to the at least one test piece and is configured to apply the first force and the second force on the at least one test piece. In some examples, the test vessel may be a hydraulic cylinder. The internal chamber defined by the hydraulic cylinder is configured to apply the steady force (i.e., the first force) and the alternating force (i.e., the second force) on the at least one test piece through the at least one test wall. Therefore, the coupling of the circumferential portion of the at least one test wall with the enclosing wall may enhance the application of the steady force (i.e., the first force) and the alternating force (i.e., the second force) on the at least one test piece.

In some embodiments, the test vessel includes a first end and a second end opposite to the first end. The enclosing wall extends between the first end and the second end. A length of the enclosing wall extending between the first end and the second end may be based on application requirements.

In some embodiments, the at least one test wall includes a first test wall defining a boundary of the internal chamber at the first end of the test vessel and a second test wall opposing the first test wall and defining a boundary of the internal chamber at the second end of the test vessel. The second fluid is configured to apply the second pressure on each of the first test wall and the second test wall. Thus, the second fluid may thereby apply the second pressure on each of the first and second test walls.

In some embodiments, the at least one test piece includes a first test piece and a second test piece. The first test wall is coupled to the first test piece and configured to apply the first force and the second force on the first test piece. The second test wall is coupled to the second test piece and configured to apply the first force and the second force on the second test piece.

Therefore, for testing the first test piece, the first test wall is configured to apply the steady force (i.e., the first force) as well as the alternating force (i.e., the second force) on the first test piece. Further, for testing the second test piece, the second test wall is configured to apply the steady force (i.e., the first force) as well as the alternating force (i.e., the second force) on the second test piece. Thus, the system of the present disclosure may be configured to test the mechanical integrity of two test pieces (the first test piece and the second test piece) simultaneously. In other words, the system of the present disclosure may impose the service representative conditions on each of the first test piece and the second test piece.

In some embodiments, the first force is substantially constant. In some examples, the first force (a substantially constant force) may be a large steady force required for testing the at least one test piece.

In some embodiments, the second force is an oscillating force having an amplitude. A magnitude of the first force is greater than the amplitude of the second force by a factor of at least <NUM>. The application of the steady force (i.e., the first force) with a relatively larger magnitude and the oscillating force (i.e., the second force) with a relatively smaller magnitude may precisely impose the service representative conditions on the at least one test piece for its testing.

In some embodiments, the system further includes a conduit fluidly communicating the second chamber with the internal chamber. The conduit may provide a means for transferring the second pressure from the second chamber of the pressure vessel to the internal chamber of the test vessel in order to apply the first force (i.e., the steady force) and the second force (i.e., the alternating force) on the at least one test piece.

According to a second aspect there is provided a method of testing at least one test piece. The method includes a step of providing a pressure vessel. The pressure vessel includes a first chamber and a second chamber fluidly separated from the first chamber by an actuating membrane. The method further includes a step of receiving a first fluid within the first chamber at a first pressure. The method further includes a step of receiving a second fluid within the second chamber. The method further includes a step of applying a first pressure, via the first fluid, on the actuating membrane. The method further includes a step of applying, via the actuating membrane, a second pressure on the second fluid within the second chamber in response to the application of the first pressure. The method further includes a step of receiving the second fluid at the second pressure within an internal chamber of a test vessel. The internal chamber is disposed in fluid communication with the second chamber. The test vessel includes at least one test wall defining at least one boundary of the internal chamber. The method further includes a step of coupling the at least one test piece to the at least one test wall. The method further includes a step of applying, via the second fluid, the second pressure on the at least one test wall. The method further includes a step of applying, via the at least one test wall, a first force on the at least one test piece in response to the application of the second pressure on the at least one test wall. The method further includes a step of applying, via an actuator, a time-varying force on the actuating membrane while the first pressure is being applied by the first fluid on the actuating membrane. The method further includes a step of applying, via the at least one test wall, a second force on the at least one test piece in addition to the first force in response to the application of the time-varying force on the actuating membrane. The second force is time-varying and is different from the first force.

In some embodiments, applying the time-varying force on the actuating membrane further includes applying, via an electromagnetic actuation device, a time-varying actuating force on a mass coupled to the actuating membrane. Applying the mevarying force on the actuating membrane further includes oscillating the mass relative to the pressure vessel to apply the time-varying force on the actuating membrane. The electromagnetic actuation device is configured to apply the time-varying force on the actuating membrane. The time-varying force on the actuating membrane further leads to application of the second force on the at least one test piece.

In some embodiments, the method further includes coupling, via a spring, the mass to the actuating membrane. By using the spring to couple the mass to the actuating membrane, the time-varying force can be applied on the actuating membrane as a result of the time-varying actuating force applied on the mass.

In some embodiments according to the method of the second aspect, the time-varying actuating force is applied on the mass at a predetermined frequency. The predetermined frequency is equal to a natural frequency of a combination of the mass and the spring. As a result, the method includes application of the time-varying force on the actuating membrane along with large displacements of the actuating membrane in response to a relatively small amount of the time-varying actuating force applied on the mass.

In some embodiments according to the method of the second aspect, the at least one test wall includes an elastic disc including a central portion. Coupling the at least one test piece to the at least one test wall further includes coupling the at least one test piece to the central portion of the elastic disc, such that the central portion of the elastic disc applies the first force and the second force on the at least one test piece. Coupling of the at least one test wall to the at least one test piece may enable application of the steady force (i.e., the first force) and the alternating force (i.e., the second force) on the at least one test piece.

In some embodiments according to the method of the second aspect, the at least one test wall includes a first test wall defining a boundary of the internal chamber at a first end of the test vessel and a second test wall opposing the first test wall and defining a boundary of the internal chamber at a second end of the test vessel. Applying the second pressure further includes applying the second pressure on each of the first test wall and the second test wall. Thus, the method of the present disclosure may enable application of the second pressure on each of the first test wall and the second test wall simultaneously.

In some embodiments according to the method of the second aspect, the at least one test piece includes a first test piece and a second test piece. Coupling the at least one test piece further includes coupling the first test piece to the first test wall, such that the first test wall applies the first force and the second force on the first test piece. Coupling the at least one test piece further includes coupling the second test piece to the second test wall, such that the second test wall applies the first force and the second force on the second test piece. The method of the present disclosure may enable testing of the mechanical integrity of two test pieces (the first test piece and the second test piece) simultaneously. In other words, the method of the present disclosure may impose the service representative conditions on each of the first test piece and the second test piece. In some embodiments according to the method of the second aspect, the first force is substantially constant. In some examples, the first force (a substantially constant force) may be a large steady force required for testing the at least one test piece.

In some embodiments according to the method of the second aspect, the second force is an oscillating force having an amplitude. A magnitude of the first force is greater than the amplitude of the second force by a factor of at least <NUM>. By the application of the steady force (i.e., the first force) with a relatively larger magnitude and the oscillating force (i.e., the second force) with a relatively smaller magnitude, the method of the present disclosure may precisely impose the service representative conditions on the at least one test piece for its testing.

<FIG> illustrates a schematic view of a system <NUM> for testing at least one test piece <NUM>, according to an embodiment of the present disclosure. In some cases, the at least one test piece <NUM> may be a mechanical component, a joint or a structure. In some cases, the at least one test piece <NUM> may be a dovetail joint of a fan blade of a gas turbine engine. In some cases, the at least one test piece <NUM> may be any other mechanical component installed in a gas turbine engine, or other prime movers. The "at least one test piece <NUM>" is interchangeably referred to hereinafter as the "test piece <NUM>".

The system <NUM> includes a pressure vessel <NUM>. The pressure vessel <NUM> includes a first chamber <NUM> receiving a first fluid F1 at a first pressure P1. The pressure vessel <NUM> further includes a second chamber <NUM> fluidly separated from the first chamber <NUM> and receiving a second fluid F2. In some embodiments, the first fluid F1 is a gas, and the second fluid F2 is a hydraulic fluid. The first fluid F1 may be a compressible gas, such as nitrogen, argon, any inert gas, a mixture of gases, and/or the like. The second fluid F2 may be any hydraulic fluid (e.g., a brake fluid). In some cases, the second fluid F2 may be a fluid based on glycol-ether, mineral oil, silicone, etc..

The pressure vessel <NUM> further includes an actuating membrane <NUM>. The actuating membrane <NUM> fluidly separates the first chamber <NUM> from the second chamber <NUM>. The actuating membrane <NUM> may be of any shape including, but not limited to, circular, rectangular, polygonal, etc. In some embodiments, the shape of the actuating membrane <NUM> may vary based on a shape and dimensions of the pressure vessel <NUM>. The actuating membrane <NUM> may include a circumferential portion or edge (not shown) coupled to an internal wall of the pressure vessel <NUM> through any coupling means. The actuating membrane <NUM> is configured to apply a second pressure P2 on the second fluid F2 within the second chamber <NUM> in response to the application of the first pressure P1 by the first fluid F1 on the actuating membrane <NUM>.

The system <NUM> further includes a test vessel <NUM> including an internal chamber <NUM> disposed in fluid communication with the second chamber <NUM> of the pressure vessel <NUM>. The system <NUM> further includes a conduit <NUM> fluidly communicating the second chamber <NUM> with the internal chamber <NUM>. In some cases, the conduit <NUM> may be a hose or a duct. In some cases, the conduit <NUM> may be rigid, or may be flexible. Further, dimensions of the conduit <NUM> may vary based on application requirements.

The internal chamber <NUM> is configured to receive the second fluid F2 at the second pressure P2. In some embodiments, the test vessel <NUM> may include a hydraulic cylinder disposed in fluid communication with the second chamber <NUM> of the pressure vessel <NUM>. The test vessel <NUM> further includes at least one test wall <NUM> defining at least one boundary of the internal chamber <NUM>. The "at least one test wall <NUM>" is interchangeably referred to hereinafter as the "test wall <NUM>". Further, the test vessel <NUM> includes a first end <NUM> and a second end <NUM> opposite to the first end <NUM>.

The test vessel <NUM> further includes an enclosing wall <NUM> at least partially defining the internal chamber <NUM>. In some cases, the enclosing wall <NUM> may include a flange connection (not shown) for coupling the test wall <NUM> to the enclosing wall <NUM>. The enclosing wall <NUM> extends between the first end <NUM> and the second end <NUM>. In some embodiments, the test vessel <NUM> is closed at the second end <NUM>. In some embodiments, the second end <NUM> may be rigidly connected to a stationary surface or component. The test vessel <NUM> may therefore be cantilevered at the second end <NUM>. A length of the enclosing wall <NUM> extending between the first end <NUM> and the second end <NUM> may be based on application requirements. Further, the test vessel <NUM> extends along a longitudinal axis LA.

The at least one test wall <NUM> is coupled to the at least one test piece <NUM>. The at least one test wall <NUM> includes an elastic disc <NUM> including a central portion <NUM> and a circumferential portion <NUM> fixedly coupled to the enclosing wall <NUM>. Specifically, the central portion <NUM> of the test wall <NUM> is coupled to the test piece <NUM>. In some embodiments, the test wall <NUM> may be a deformable wall. In some cases, the elastic disc <NUM> may be a metallic disc. The circumferential portion <NUM> may be connected to the enclosing wall <NUM> through a flange connection (not shown) to fixedly couple the elastic disc <NUM> to the enclosing wall <NUM> of the test vessel <NUM>. Further, the central portion <NUM> may be deformable relative to the circumferential portion <NUM>. In some cases, a thickness of the central portion <NUM> may be less than a thickness of the circumferential portion <NUM> to facilitate deformation of the central portion <NUM>.

Further, the at least one test wall <NUM> is configured to apply a first force N1 on the at least one test piece <NUM> in response to the application of the second pressure P2 by the second fluid F2 on the at least one test wall <NUM>. In some embodiments, the first force N1 is substantially constant. In other words, the first force N1 may show negligible variation with time. For example, a maximum variation of the first force N1 may be less than or equal to <NUM>% of a desired magnitude. Moreover, the central portion <NUM> is configured to apply the first force N1 on the test piece <NUM>.

The system <NUM> further includes an actuator <NUM> engaged with the actuating membrane <NUM> of the pressure vessel <NUM>. The actuator <NUM> includes a mass <NUM> coupled to the actuating membrane <NUM>. The actuator <NUM> further includes an electromagnetic actuation device <NUM> disposed proximal to the mass <NUM>. In some embodiments, the electromagnetic actuation device <NUM> is a direct current linear actuator. In some cases, the electromagnetic actuation device <NUM> may include a magnetic field assembly (not shown) and a coil winding (not shown). In some cases, the electromagnetic actuation device <NUM> may be a voice coil actuator. The actuator <NUM> further includes a spring <NUM> coupling the mass <NUM> to the actuating membrane <NUM>. In the illustrated embodiment of <FIG>, the spring <NUM> includes a mechanical spring <NUM>-<NUM>, for example, a coil spring.

The electromagnetic actuation device <NUM> is configured to apply a time-varying actuating force N3 on the mass <NUM>, such that the mass <NUM> oscillates relative to the pressure vessel <NUM> to apply a time-varying force N4 on the actuating membrane <NUM>. The electromagnetic actuation device <NUM> uses a flow of current to oscillate the mass <NUM> relative to the pressure vessel <NUM>. In other words, the electromagnetic actuation device <NUM> may provide an energy to excite the mass <NUM> relative to the pressure vessel <NUM> to apply the time-varying force N4 on the actuating membrane <NUM>.

In some embodiments, the electromagnetic actuation device <NUM> is further configured to apply the time-varying actuating force N3 on the mass <NUM> at a predetermined frequency. In some embodiments, the predetermined frequency is equal to a natural frequency of a combination of the mass <NUM> and the spring <NUM>. As the predetermined frequency is equal to the natural frequency of the combination of the mass <NUM> and the spring <NUM>, the mass <NUM> and the spring <NUM> may oscillate at resonance. As a result, a relatively small amount of the time-varying actuating force N3 applied on the mass <NUM> may transform into the time-varying force N4 applied on the actuating membrane <NUM> along with large displacements of the actuating membrane <NUM>. In some cases, the electromagnetic actuation device <NUM> (e.g., the voice coil actuator) may apply the time-varying actuating force N3 on the mass <NUM> at a high frequency.

As stated above, the actuating membrane <NUM> is configured to apply the second pressure P2 on the second fluid F2 within the second chamber <NUM> in response to the application of the first pressure P1 by the first fluid F1 on the actuating membrane <NUM>. Therefore, the actuator <NUM> is configured to apply the time-varying force N4 on the actuating membrane <NUM> while the first pressure P1 is being applied by the first fluid F1 on the actuating membrane <NUM>.

The at least one test wall <NUM> is further configured to apply a second force N2 on the at least one test piece <NUM> in addition to the first force N1 in response to the application of the time-varying force N4 by the actuator <NUM> on the actuating membrane <NUM>. The second force N2 is time-varying and is different from the first force N1. In some embodiments, the first force N1 may be a high magnitude steady force and the second force N2 may be time-varying force of relatively lower magnitude. The central portion <NUM> of the test wall <NUM> is configured to apply the second force N2 on the test piece <NUM>. Therefore, the central portion <NUM> of the test wall <NUM> is configured to apply the first force N1 as well as the second force N2 on the test piece <NUM>.

In some embodiments, the second force N2 is an oscillating force having an amplitude. In some embodiments, a magnitude of the first force N1 is greater than the amplitude of the second force N2 by a factor of at least <NUM>. In some embodiments, the magnitude of the first force N1 may vary from about <NUM> bars to about <NUM> bars and the amplitude of the second force N2 may vary from about <NUM> bars to <NUM> bars. Further, it should be noted that during the application of the first force N1 and the second force N2 on the test piece <NUM>, the central portion <NUM> may move relative to the circumferential portion <NUM> of the elastic disc <NUM>. Specifically, the central portion <NUM> of the elastic disc <NUM> applies the first force N1 and the second force N2 on the test piece <NUM> in a direction along the longitudinal axis LA.

<FIG> is a schematic view of a system <NUM> for testing the at least one test piece <NUM>, according to another embodiment of the present disclosure. The system <NUM> is substantially similar to the system <NUM> illustrated in <FIG>, with common components being referred to by the same reference numerals. However, in the system <NUM>, the spring <NUM> includes a spring membrane <NUM>-<NUM> (instead of the mechanical spring <NUM>-<NUM> shown in <FIG>) disposed in the first chamber <NUM> and an enclosed fluid F3 disposed between the spring membrane <NUM>-<NUM> and the actuating membrane <NUM>. Further, the spring membrane <NUM>-<NUM> is coupled to the mass <NUM>. In some cases, the enclosed fluid F3 may be same as the first fluid F1. The enclosed fluid F3, without limiting the scope of the disclosure, may also be a fluid other than the first fluid F1 and the second fluid F2.

As stated above, the electromagnetic actuation device <NUM> is configured to apply the time-varying actuating force N3 on the mass <NUM> at a predetermined frequency, such that the mass <NUM> oscillates relative to the pressure vessel <NUM> to apply the time-varying force N4 on the actuating membrane <NUM>. In the illustrated embodiment of <FIG>, by coupling the spring membrane <NUM>-<NUM> to the mass <NUM>, the time-varying force N4 is applied on the actuating membrane <NUM> via the enclosed fluid F3 in response to the time-varying actuating force N3 applied on the spring membrane <NUM>-<NUM>.

<FIG> is a schematic view of a system <NUM> for testing the at least one test piece <NUM>, according to an embodiment of the present disclosure. The system <NUM> is substantially similar to the system <NUM> illustrated in <FIG>, with common components being referred to by the same reference numerals. However, in the system <NUM>, the at least one test piece <NUM> includes a first test piece <NUM>-<NUM> and a second test piece <NUM>-<NUM>. Therefore, in the illustrated embodiment of <FIG>, the system <NUM> may be able to test two test pieces (i.e., the first test piece <NUM>-<NUM> and the second test piece <NUM>-<NUM>). In some embodiments, the second test piece <NUM>-<NUM> may be substantially similar to the first test piece <NUM>-<NUM>. In some other cases, the second test piece <NUM>-<NUM> may be different from the first test piece <NUM>-<NUM>.

Referring to <FIG>, the at least one test wall <NUM> includes a first test wall <NUM>-<NUM> defining a boundary of the internal chamber <NUM> at the first end <NUM> of the test vessel <NUM>. Further, the at least one test wall <NUM> includes a second test wall <NUM>-<NUM> defining a boundary of the internal chamber <NUM> at the second end <NUM> of the test vessel <NUM>. Therefore, in the illustrated embodiment of <FIG>, the at least one test wall <NUM> includes two test walls (i.e., the first test wall <NUM>-<NUM> and the second test wall <NUM>-<NUM>). In some embodiments, the second test wall <NUM>-<NUM> is substantially similar to the first test wall <NUM>-<NUM>. In other embodiments, the second test wall <NUM>-<NUM> may be different from the first test wall <NUM>-<NUM>. Further, the second fluid F2 is configured to apply the second pressure P2 on each of the first test wall <NUM>-<NUM> and the second test wall <NUM>-<NUM>.

In the illustrated embodiment of <FIG>, the first test wall <NUM>-<NUM> is coupled to the first test piece <NUM>-<NUM>. The second test wall <NUM>-<NUM> is coupled to the second test piece <NUM>-<NUM>. The first test wall <NUM>-<NUM> is configured to apply the first force N1 on the first test piece <NUM>-<NUM> in response to the application of the second pressure P2 by the second fluid F2 on the first test wall <NUM>-<NUM>. The second test wall <NUM>-<NUM> is configured to apply the first force N1 on the second test piece <NUM>-<NUM> in response to the application of the second pressure P2 by the second fluid F2 on the second test wall <NUM>-<NUM>.

The first test wall <NUM>-<NUM> is further configured to apply the second force N2 on the first test piece <NUM>-<NUM> in addition to the first force N1 in response to the application of the time-varying force N4 by the actuator <NUM> on the actuating membrane <NUM>. The second test wall <NUM>-<NUM> is further configured to apply the second force N2 on the second test piece <NUM>-<NUM> in response to the application of the time-varying force N4 by the actuator <NUM> on the actuating membrane <NUM>. Therefore, the first test wall <NUM>-<NUM> is configured to apply the first force N1 and the second force N2 on the first test piece <NUM>-<NUM>. Further, the second test wall <NUM>-<NUM> is configured to apply the first force N1 and the second force N2 on the second test piece <NUM>-<NUM>. Hence, for testing the first test piece <NUM>-<NUM> and the second test piece <NUM>-<NUM>, the system <NUM> is configured to apply the first force N1 and the second force N2 on each of the first test piece <NUM>-<NUM> and the second test piece <NUM>-<NUM>.

<FIG> is an exemplary graph <NUM> illustrating the first force N1 and the second force N2 applied by the at least one test wall <NUM> (shown in <FIG>) on the at least one test piece <NUM> (shown in <FIG>). As illustrated in the graph <NUM>, force is depicted in arbitrary units (a. ) on the ordinate. Time is depicted on the abscissa.

Referring to <FIG>, the graph <NUM> illustrates a steady line <NUM> depicting the first force N1 which is substantially constant with respect to time. The first force N1 is applied by the at least one test wall <NUM> on the at least one test piece <NUM> in response to the application of the second pressure P2 by the second fluid F2 on the at least one test wall <NUM>.

The graph <NUM> further illustrates a curve <NUM> depicting the variation of the second force N2 with respect to time. In some cases, the curve <NUM> may be a sinusoidal curve. Further, it should be noted that the curve <NUM> is symmetric with respect to the steady line <NUM> depicting the first force N1. The second force N2 is applied by the at least one test wall <NUM> on the at least one test piece <NUM> in response to the application of the time-varying force N4 by the actuator <NUM> on the actuating membrane <NUM>. In the illustrated curve <NUM> of the graph <NUM>, the second force N2 oscillates between higher amplitude points (illustrated by point B) and crosses the low amplitude points (illustrated by point A).

Referring to <FIG>, for testing the at least one test piece <NUM>, each of the systems <NUM>, <NUM>, <NUM> may apply the first force N1 as well as the second force N2 on the at least one test piece <NUM>. As the first force N1 is applied in response to the application of the second pressure P2 by the second fluid F2 on the at least one test wall <NUM>, the first force N1 may be a steady force (e.g., a hydraulic force). Further, the first force N1 may provide a large steady force required for testing the at least one test piece <NUM>.

Each of the systems <NUM>, <NUM>, <NUM> is further configured to apply the second force N2 on the at least one test piece <NUM> in response to the application of the time-varying force N4 by the actuator <NUM> on the actuating membrane <NUM>. Further, as the second force N4 is applied in response to the application of the time-varying force N4, the second force N2 may be an alternating force required for testing the at least one test piece <NUM>. Hence, each of the systems <NUM>, <NUM>, <NUM> may be configured to apply the alternating force (i.e., the second force N2) in addition to the steady force (i.e., the first force N1) on the at least one test piece <NUM> for testing the at least one test piece <NUM>.

Generally, in real time operations involving the use of the at least one test piece <NUM>, the at least one test piece <NUM> may be subjected to various loads generated by steady forces as well as alternating forces (i.e., time-varying forces). Such forces may correspond to service representative conditions of the at least one test piece <NUM>. Each of the systems <NUM>, <NUM>, <NUM> may enable the application of the steady force (i.e., the first force N1) as well as the alternating force (i.e., the second force N2) on the at least one test piece <NUM> for testing a durability and a mechanical integrity of the at least one test piece <NUM>. Hence, each of the systems <NUM>, <NUM>, <NUM> of the present disclosure may impose the service representative conditions on the at least one test piece <NUM> by applying the alternating force in addition to the constant fluid force on the at least one test piece <NUM>.

As compared to conventional techniques for testing the mechanical integrity of a test piece by applying only a hydraulic force, each of the systems <NUM>, <NUM>, <NUM> may utilize a single setup for applying both the steady force (i.e., the first force N1) as well as the alternating force (i.e., the second force N2) in order to test the mechanical integrity of the at least one test piece <NUM>. In other words, each of the systems <NUM>, <NUM>, <NUM> uses the single setup for generating and imposing the service representative conditions on the at least one test piece <NUM>. Thus, each of the systems <NUM>, <NUM>, <NUM> may be able to accurately determine the durability and the mechanical integrity of the at least one test piece <NUM>.

Further, as already stated above, the predetermined frequency of the time-varying actuating force N3 applied on the mass <NUM> is equal to the natural frequency of the combination of the mass <NUM> and the spring <NUM>. As a result, small oscillations of the mass <NUM> may transform into a greater value of the time-varying force N4 applied on the actuating membrane <NUM> along with large displacements of the actuating membrane <NUM>. As compared to a conventional piezo electric actuation system, the actuator <NUM> of each of the systems <NUM>, <NUM>, <NUM> may apply the alternating force (i.e., the second force N2) on the at least one test piece <NUM> with small displacements as well as large displacements of the actuating membrane <NUM> and/or the at least one test piece <NUM>. The service representative conditions imposed on the at least one test piece <NUM> may include small displacements as well as large displacements of the at least one test piece <NUM>.

Moreover, by imposing the service representative conditions on the at least one test piece <NUM>, a service life of the at least one test piece <NUM> may be determined. This may further help in predicting a time for next inspection of the at least one test piece <NUM> after the at least one test piece <NUM> is put into service.

Referring again to <FIG>, the system <NUM> may be configured to test the mechanical integrity of two test pieces (the first test piece <NUM>-<NUM> and the second test piece <NUM>-<NUM>). In other words, the system <NUM> may impose the service representative conditions on each of the first test piece <NUM>-<NUM> and the second test piece <NUM>-<NUM>.

<FIG> is a flowchart illustrating a method <NUM> of testing at least one test piece <NUM>, according to an embodiment of the present disclosure. The method may be implemented using the systems <NUM>, <NUM>, <NUM> described with reference to <FIG>. In some embodiments, the at least one test piece <NUM> includes the first test piece <NUM>-<NUM> and the second test piece <NUM>-<NUM>.

Referring to <FIG>, at step <NUM>, the method <NUM> includes providing the pressure vessel <NUM>. The pressure vessel <NUM> includes the first chamber <NUM> and the second chamber <NUM> fluidly separated from the first chamber <NUM> by the actuating membrane <NUM>.

At step <NUM>, the method <NUM> further includes receiving the first fluid F1 within the first chamber <NUM> at the first pressure P1. At step <NUM>, the method further includes receiving the second fluid F2 within the second chamber <NUM>. At step <NUM>, the method <NUM> further includes applying the first pressure P1, via the first fluid F1, on the actuating membrane <NUM>. At step <NUM>, the method <NUM> further includes applying, via the actuating membrane <NUM>, the second pressure P2 on the second fluid F2 within the second chamber <NUM> in response to the application of the first pressure P1.

At step <NUM>, the method <NUM> further includes receiving the second fluid F2 at the second pressure P2 within the internal chamber <NUM> of the test vessel <NUM>. The internal chamber <NUM> is disposed in fluid communication with the second chamber <NUM>. The test vessel <NUM> includes at least one test wall <NUM> defining the at least one boundary of the internal chamber <NUM>. In some embodiments, the at least one test wall <NUM> includes the elastic disc <NUM> including the central portion <NUM>. In some embodiments, the at least one test wall <NUM> includes the first test wall <NUM>-<NUM> defining the boundary of the internal chamber <NUM> at the first end <NUM> of the test vessel <NUM>. The at least one test wall <NUM> further includes the second test wall <NUM>-<NUM> (shown in <FIG>) opposing the first test wall <NUM>-<NUM> and defining the boundary of the internal chamber <NUM> at the second end <NUM> of the test vessel <NUM>.

At step <NUM>, the method <NUM> further includes coupling the at least one test piece <NUM> to the at least one test wall <NUM>. In some embodiments, coupling the at least one test piece <NUM> further includes coupling the first test piece <NUM>-<NUM> to the first test wall <NUM>-<NUM> and coupling the second test piece <NUM>-<NUM> (shown in <FIG>) to the second test wall <NUM>-<NUM>. In some embodiments, coupling the at least one test piece <NUM> to the at least one test wall <NUM> further includes coupling the at least one test piece <NUM> to the central portion <NUM> of the elastic disc <NUM>.

At step <NUM>, the method <NUM> further includes applying via the second fluid F2, the second pressure P2 on the at least one test wall <NUM>. In some embodiments, applying the second pressure P2 further includes applying the second pressure P2 on each of the first test wall <NUM>-<NUM> and the second test wall <NUM>-<NUM> (shown in <FIG>).

At step <NUM>, the method <NUM> further includes applying via the at least one test wall <NUM>, the first force N1 on the at least one test piece <NUM> in response to the application of the second pressure P2 on the at least one test wall <NUM>. In some embodiments, the central portion <NUM> of the elastic disc <NUM> applies the first force N1 on the at least one test piece <NUM>. Further, in some embodiments, the first test wall <NUM>-<NUM> applies the first force N1 on the first test piece <NUM>-<NUM> and the second test wall <NUM>-<NUM> applies the first force N1 on the second test piece <NUM>-<NUM> (shown in <FIG>). In some embodiments, the first force N1 is substantially constant.

At step <NUM>, the method <NUM> further includes applying via the actuator <NUM>, the time-varying force N4 on the actuating membrane <NUM> while the first pressure P1 is being applied by the first fluid F1 on the actuating membrane <NUM>. In some embodiments, applying the time-varying force N4 on the actuating membrane <NUM> further includes applying via the electromagnetic actuation device <NUM>, the time-varying actuating force N3 on the mass <NUM> coupled to the actuating membrane <NUM>. In some embodiments, the method <NUM> further includes coupling via the spring <NUM>, the mass <NUM> to the actuating membrane <NUM>. In some embodiments, the time-varying actuating force N3 is applied on the mass <NUM> at the predetermined frequency. In some embodiments, the predetermined frequency is equal to the natural frequency of the combination of the mass <NUM> and the spring <NUM>. In some embodiments, applying the time-varying force N4 on the actuating membrane <NUM> further includes oscillating the mass <NUM> relative to the pressure vessel <NUM> to apply the time-varying force N4 on the actuating membrane <NUM>. At step <NUM>, the method <NUM> further includes applying, via the at least one test wall <NUM>, the second force N2 on the at least one test piece <NUM> in addition to the first force N1 in response to the application of the time-varying force N4 on the actuating membrane <NUM>. The second force N2 is time-varying and is different from the first force N1. In some embodiments, the central portion <NUM> of the elastic disc <NUM> applies the second force N2 on the at least one test piece <NUM>. In some embodiments, the first test wall <NUM>-<NUM> applies the second force N2 on the first test piece <NUM>-<NUM> and the second test wall <NUM>-<NUM> applies the second force N2 on the second test piece <NUM>-<NUM>. In some embodiments, the second force N2 is the oscillating force having the amplitude. The magnitude of the first force N1 is greater than the amplitude of the second force N2 by a factor of at least <NUM>.

Claim 1:
A system (<NUM>, <NUM>, <NUM>) for testing at least one test piece (<NUM>), the system (<NUM>, <NUM>, <NUM>) comprising:
a pressure vessel (<NUM>) comprising:
a first chamber (<NUM>) receiving a first fluid (F1) at a first pressure (P1);
a second chamber (<NUM>) fluidly separated from the first chamber (<NUM>) and receiving a second fluid (F2); and
an actuating membrane (<NUM>) fluidly separating the first chamber (<NUM>) from the second chamber (<NUM>), wherein the actuating membrane (<NUM>) is configured to apply a second pressure (P2) on the second fluid (F2) within the second chamber (<NUM>) in response to the application of the first pressure (P1) by the first fluid (F1) on the actuating membrane (<NUM>);
a test vessel (<NUM>) comprising an internal chamber (<NUM>) disposed in fluid communication with the second chamber (<NUM>) and at least one test wall (<NUM>) defining at least one boundary of the internal chamber (<NUM>), wherein the at least one test wall (<NUM>) is coupled to the at least one test piece (<NUM>), wherein the internal chamber (<NUM>) is configured to receive the second fluid (F2) at the second pressure (P2), and wherein the at least one test wall (<NUM>) is configured to apply a first force (N1) on the at least one test piece (<NUM>) in response to the application of the second pressure (P2) by the second fluid (F2) on the at least one test wall (<NUM>); and
an actuator (<NUM>) engaged with the actuating membrane (<NUM>) and configured to apply a time-varying force (N4) on the actuating membrane (<NUM>) while the first pressure (P1) is being applied by the first fluid (F1) on the actuating membrane (<NUM>),
wherein the at least one test wall (<NUM>) is further configured to apply a second force (N2) on the at least one test piece (<NUM>) in addition to the first force (N1) in response to the application of the time-varying force (N4) by the actuator (<NUM>) on the actuating membrane (<NUM>), and wherein the second force (N2) is time-varying and is different from the first force (N1).