Impact load test device

Abstract

The invention provides an impact load test device, which comprises a supporting piece, an impact piece and a loading clamp, and is characterized in that the supporting piece is used for supporting and fixing a test piece; the impact part is used for providing impact force; the loading clamp comprises a connecting part, a load distribution ball and a switching part, the connecting part is used for providing a connecting surface rigidly connected with the test piece, the switching part is used for connecting the load distribution ball and the connecting part, and the load distribution ball is used for receiving impact force and converting the impact force into a multi-dimensional impact load; wherein at least part of the switching part has different damping coefficients so as to change the transmission time of loads in different directions. The impact load test device can simulate multi-dimensional load impact and truly simulate load loading time.

Description

Technical Field

[0001] The invention relates to the field of aero-engine testing, and in particular to the field of impact testing. Background Art

[0002] During the operation of aircraft engines, they may encounter load impacts such as blade loss and bird strikes. The characteristics of such loads are usually high-speed, high-energy, transient impact loads. When performing extreme load strength assessments such as blade loss and bird strikes, key aircraft engine components, such as load-bearing frames, mounting systems, and support systems, need to be loaded with impact loads of the same characteristics.

[0003] In order to reproduce the ultimate load state of aircraft engines, tests are usually carried out using fixed high-speed gas guns with an impact speed of more than 200m / s. However, the following problems still exist: the ultimate load of aircraft engines is usually above 100 tons, which is difficult to achieve with the above conventional test loading methods; the ultimate load of aircraft engines is usually a time history load with a load action time of 10ms-50ms. The projectile and test piece fired by fixed high-speed gas guns have a conventional action time of less than 1ms-2ms, so the load action time needs to be extended; the ultimate load of aircraft engines is usually decomposed into three directions: x, y, and z. Loading methods such as fixed high-speed gas guns, drop hammers, and pendulums can only load in one direction; the ultimate load of aircraft engines has different load action time histories in the three directions of x, y, and z, and the three curves reach their peak values ​​at different times.

[0004] In view of this, it is necessary to propose an impact load test device to solve the above problems. Summary of the invention

[0005] An object of the present invention is to provide an impact load testing device that can accurately simulate boundary constraints and multi-dimensional input load characteristics.

[0006] In order to achieve the above-mentioned destination, an impact load test device is used for impact testing of a test piece, including a support member, an impact member and a loading fixture, wherein the support member is used to support and fix the test piece; the impact member is used to provide an impact force; the loading fixture includes a connecting part, a load distribution ball and a transition part, the connecting part is used to provide a connecting surface rigidly connected to the test piece, the transition part is used to connect the load distribution ball and the connecting part, and the load distribution ball is used to receive the impact force and convert it into a multi-dimensional impact load; wherein at least part of the transition part has different damping coefficients to change the transmission time of loads in different directions.

[0007] In one or more embodiments, the transition part includes a load distribution ring, a plurality of damping members and a connecting rod, wherein the load distribution ring is connected to the load distribution ball in different directions through each of the damping members, and the connecting part is connected through each of the connecting rods, and at least some of the damping members have different damping coefficients.

[0008] In one or more embodiments, the number, position and diameter of the connecting rods are adjustable, and the extension direction and damping coefficient of the damping element are adjustable.

[0009] In one or more embodiments, the impact piece includes a plurality of replacement pieces having different lengths and / or different cross-sectional areas to adjust the load loading time and / or load magnitude by virtue of its own length and / or contact area with the load distribution ball.

[0010] In one or more embodiments, the impact piece is fired by a high-speed gas gun, or loaded by a drop weight or a pendulum.

[0011] In one or more embodiments, the transition portion includes an expansion end and a contraction end, the expansion end is connected to the connection portion, and the contraction end is connected to the load distribution ball.

[0012] In one or more embodiments, strain gauges are provided on the support member and / or the loading fixture.

[0013] In one or more embodiments, the supporting member includes a rod member and an elastic member.

[0014] In one or more embodiments, the connection position between the rod and the test piece is configured to be adjustable, and the diameter and number of the rods and the elastic coefficient of the elastic member are configured to be changeable.

[0015] In one or more embodiments, the connecting portion is an adapter disk or an adapter ring.

[0016] The above-mentioned impact load test device converts the unidirectional impact force transmitted by the impact part into a multi-dimensional impact load through a load distribution ball, and adjusts the time sequence of loading the load curve by designing a transition part with different damping coefficients, thereby transmitting a more realistic and accurate impact load to the test part; it also provides impact parts of multiple specifications, provides the load impact time and size required for the impact test, and improves the reliability of the impact test. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0018] Figure 1 is an oblique view of an embodiment of an impact load test device in cooperation with a test piece;

[0019] Figure 2 is a front view of an embodiment of an impact load test device in cooperation with a test piece;

[0020] Figure 3 is a top view of an embodiment of an impact load test device in cooperation with a test piece;

[0021] Figure 4 is a schematic diagram of one embodiment of a loading fixture;

[0022] Figure 5 is a schematic diagram of an embodiment of a support member.

[0023] Symbols and Markings

[0024] 5 Test pieces

[0025] 10 Support

[0026] 11 Rod

[0027] 12 Elastic parts

[0028] 20 Impact piece

[0029] 30 Loading fixture

[0030] 31 Connection

[0031] 32 Load distribution ball

[0032] 33 Transfer Unit

[0033] 301 Expansion End

[0034] 302 Contraction end

[0035] 331 Load Distribution Ring

[0036] 332 Damping parts

[0037] 333 Connecting rod DETAILED DESCRIPTION

[0038] The present invention is further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description herein. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0039] It should be noted that these and other subsequent drawings are only examples and are not drawn to scale, and should not be used to limit the actual scope of protection required by the present invention.

[0040] An aircraft engine is a highly complex and sophisticated thermal machine, consisting of an inlet, a high-pressure compressor, a low-pressure compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine, and a tail nozzle. The ultimate load is the maximum load that an aircraft engine may encounter during operation, such as blade loss, bird strike, etc. The ultimate load is usually characterized by a high-speed, high-energy, transient impact load, so the impact test is a test conducted to reproduce the ultimate load state of an aircraft engine.

[0041] The impact load testing device disclosed in the present invention is used for impact testing of a test piece 5, which is an ultimate load strength test of key parts of an aircraft engine, such as a load-bearing frame, a mounting system, a support system, etc.

[0042] like Figure 1-3 As shown, the impact load test device includes a support member 10, an impact member 20 and a loading fixture 30. The support member 10 is used to support and fix the test piece 5, and provide the test piece 5 with the same installation stiffness as its actual installation state in the aircraft engine.

[0043] The impact member 20 is used to provide an impact force. In one embodiment, the impact member 20 includes a plurality of replacement members having different lengths and / or different cross-sectional areas, so as to adjust the load loading time and / or load magnitude by virtue of its own length and / or the contact area with the load distribution ball 32. Figure 3 The long bullet design shown in the figure can be made of but not limited to solid round rods. The rod diameter and length are designed according to the load curve required for loading. The longer the loading time required, the longer the round rod length. Figure 1 The load curve of the test piece 1 is shown as being loaded for a sufficiently long time; the greater the load required for loading, the larger the rod diameter is, and the limit load level is met. The impact piece 20 is fired by, but not limited to, a fixed high-speed gas gun, and can also be loaded at the same speed by a drop hammer or a pendulum. Through the above design, the impact piece 20 loads the test piece 5 with a limit input load of the same magnitude and time history as the limit load it is subjected to in the aircraft engine, thereby improving the test accuracy.

[0044] Specific reference Figure 4 In one example shown, the loading fixture 30 includes a connection portion 31, a load distribution ball 32, and an adapter portion 33. The connection portion 31 is used to provide a connection surface rigidly connected to the test piece 5. According to the characteristics of the test piece installation surface, the connection portion 31 can be an adapter plate, an adapter ring, or other connection structures. Its functional feature is to provide a rigid connection interface between the loading fixture and the test piece, so that the load of the loading fixture can be effectively transmitted. The adapter plate includes but is not limited to a circular structure.

[0045] The load distribution ball 32 is used to receive the impact force and convert it into a multi-dimensional impact load. The load distribution ball 32 can be a solid sphere but is not limited to a solid sphere. Its function is to Figure 1 The axial load along the X direction loaded on the long bullet impact piece 20 fired by the fixed high-speed air gun is converted into loads in the axial X, vertical Y, and transverse Z directions. The load ratios in the three directions can be calculated through the contact position between the long bullet and the sphere.

[0046] The adapter 33 is used to connect the load distribution ball 32 and the connection part 31, wherein at least part of the adapter 33 has different damping coefficients to change the transmission time of loads in different directions. In a specific embodiment, this is achieved by providing a damping member. Figure 4 As shown, the adapter 33 includes a load distribution ring 331, a plurality of damping elements 332 and a connecting rod 333. The load distribution ring 331 is connected to the load distribution ball 32 in different directions through each damping element 332, and is connected to the above-mentioned connecting part 31 through each connecting rod 333. At least some of the damping elements 332 have different damping coefficients. For example, the vertical and lateral loads converted by the load distribution ball 32 are delayed by using damping elements or different materials to adjust the time sequence of the load curve loading. The extension direction and damping coefficient of the damping element 332 are adjustable, so as to be adjusted according to different load action times, so that the impact load test device provides accurate input load characteristics and boundary constraints.

[0047] In other damping setting modes, a hollow portion may be provided in the transition portion to generate a rod-like transfer structure, and different damping coefficients may be given to the rod-like transfer structure to adjust the load transfer time. In addition, the load distribution ball 32 may be directly connected to the connecting ring through the damping member.

[0048] The load distribution ring 331 is used to connect the load distribution ball 32 and the connecting part 31. Figure 4 The adapter plate structure shown transmits loads in different directions through the connecting rod 333 and the adapter plate to the test piece 5. The connecting rod 333 and the adapter plate are designed according to the input load so that they work in the elastic section of the material without yielding during the test. Under this assumption, the load of the load distribution ring 331 will be transmitted to the test piece 5 in a 1:1 ratio.

[0049] The connecting rod 333 may be a solid round rod, but is not limited to a solid round rod. Its function is to connect the load distribution ring 331 and the adapter plate. According to the magnitude of the impact load, including but not limited to the position, quantity and diameter shown in the figure, if necessary, two inner and outer connecting rods may be provided to transfer a larger load. The input load curve may also be measured by pasting a strain gauge on the connecting rod 333. The connecting rod includes but is not limited to a round rod, and includes but is not limited to a solid rod.

[0050] The adapter 33 includes an expansion end 301 and a contraction end 302. The expansion end 301 is connected to the connection part 31, and the contraction end 302 is connected to the load distribution ball 32 to facilitate the transmission of force. Figure 1 and Figure 4 After the impact member 20 impacts the load distribution ball 32 in the initial X direction, the loading fixture 30 can transmit the original X direction load by itself, and transmit the Y and Z direction loads along the damping member 332 in the Y and Z directions respectively, thereby realizing multi-dimensional transmission of the load, solving the problem that traditional loading methods such as fixed high-speed air guns, drop hammers, and pendulums can only load in one direction, and making the extreme input load have a more realistic time history.

[0051] The support member 10 is a supporting and fixing structure for the test piece 5, and needs to keep the test piece in a fixed position in space. Figure 5 As shown, the support member 10 includes a rod 11 and an elastic member 12. The support rod 11 can be, but is not limited to, a solid round rod. Support rods of different diameters, numbers, and positions can be set according to the mass of the test piece. The elastic coefficient of the elastic member 12 is also set to be able to change according to different impact loads. The elastic member 12 can be, but is not limited to, Figure 3 The functional characteristic of the coil spring shown is to provide additional stiffness to be equivalent to the installation stiffness of the test piece in the aircraft engine. Springs with different elastic coefficients are installed on different support rods 11 to simulate the actual installation state of the test piece with changes in the installation boundary stiffness.

[0052] In one embodiment, the output load curve is measured by providing strain gauges on the support 10 and / or the loading fixture 30 .

[0053] The above-mentioned impact load test device loads the test piece with an ultimate input load of the same magnitude and time history as the ultimate load it is subjected to in the aircraft engine, and provides a mounting stiffness identical to its actual mounting state in the aircraft engine, thereby effectively ensuring that the test piece has the boundary constraints and input load characteristics when the aircraft engine is running.

[0054] The present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or multiple times in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0055] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. An impact load test device for impact testing a test piece (5), characterized in that: include: A support member (10) for supporting and fixing the test member (5); An impact member (20) for providing an impact force; as well as A loading fixture (30) comprises a connecting portion (31), a load distribution ball (32) and a transition portion (33), wherein the connecting portion (31) is used to provide a connecting surface rigidly connected to the test piece (5), the transition portion (33) is used to connect the load distribution ball (32) and the connecting portion (31), and the load distribution ball (32) is used to receive the impact force and convert it into a multi-dimensional impact load; Wherein, at least part of the transition portion (33) has different damping coefficients to change the transmission time of loads in different directions.

2. The impact load testing device according to claim 1, characterized in that: The transition part (33) comprises a load distribution ring (331), a plurality of damping elements (332) and a connecting rod (333); the load distribution ring (331) is connected to the load distribution ball (32) in different directions via the damping elements (332), and is connected to the connecting part (31) via the connecting rods (333); at least some of the damping elements (332) have different damping coefficients.

3. The impact load testing device according to claim 2, characterized in that: The number, position and diameter of the connecting rod (333) are adjustable, and the extension direction and damping coefficient of the damping member (332) are adjustable.

4. The impact load testing device according to claim 1, characterized in that: The impact piece (20) includes a plurality of replacement pieces with different lengths and / or different cross-sectional areas, so as to adjust the load loading time and / or load magnitude by virtue of its own length and / or contact area with the load distribution ball (32).

5. The impact load testing device according to claim 1, characterized in that: The impact piece (20) is fired by a high-speed gas gun, or loaded by a drop weight or a pendulum.

6. The impact load testing device according to claim 1, characterized in that: The transition part (33) comprises an expansion end (301) and a contraction end (302), wherein the expansion end (301) is connected to the connection part (31), and the contraction end (302) is connected to the load distribution ball (32).

7. The impact load testing device according to claim 1, characterized in that: The support member (10) and / or the loading fixture (30) are provided with strain gauges.

8. The impact load testing device according to claim 1, characterized in that: The support member (10) comprises a rod member (11) and an elastic member (12).

9. The impact load testing device according to claim 8, characterized in that: The connection position between the rod (11) and the test piece (5) is configured to be adjustable, and the diameter and number of the rod (11) and the elastic coefficient of the elastic piece (12) are configured to be changeable.

10. The impact load testing device according to claim 1, characterized in that: The connecting portion (31) is an adapter disc or an adapter ring.

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