Test boundary design method and system for reverse deduction of load

Abstract

The present invention provides a method and system for designing a test boundary by reverse deduction of load, comprising the following steps: Step 1: Determine the boundary conditions and the loading form of the specimen; Step 2: Design an initial tooling according to the boundary conditions and the loading form, combined with the interface form of the specimen; Step 3: Establish a finite element analysis model structure of the initial tooling, apply force to the specimen, apply the load of the specimen in reverse to the initial tooling, and obtain the deformation structure of the initial tooling through finite element analysis; Step 4: Improve the design configuration of the initial tooling according to the deformation structure of the initial tooling and the interface form, and obtain the final tooling applied to the specimen test. The method proposed by the present invention is suitable for the requirements for the uniformity of load application, and the test boundary design in the compression test with single-point loading of the tooling has obvious improvement and improvement on the phenomenon of uneven load application.

Description

Technical Field

[0001] The invention relates to the technical field of single-point loading compression testing, and in particular to a test boundary design method and system for reverse derivation of loading. Background Art

[0002] In the single-point loading compression test of the specimen, the force generated by the loading source is applied to the specimen through the tooling, and the force transmission performance of the loading tooling is an important issue that needs to be considered in the tooling boundary design. In order to more realistically and comprehensively evaluate the structure, in the tooling design process, it is necessary to reasonably design the tooling according to the loading form, boundary conditions and interface of the specimen. However, due to the limitations of the specimen size and loading method, it is difficult to apply the single-point loading load evenly to the specimen. In the single-point loading compression test that requires uniform load application, if there is no reasonable tooling boundary, the load cannot be evenly transferred to the specimen through the loading tooling during the test loading process. The test results will deviate greatly from the actual results, and the test data obtained are difficult to apply to engineering practice, and lose their reference function.

[0003] The patent document with publication number CN106813885A discloses a mobile mass test device and test method that can simulate multiple boundary conditions, including a motor, a single-wheeled mobile trolley, a specimen plate, a support pier and a base, the support pier is fixed on the base, a fixture device is provided on the support pier, the specimen plate is correspondingly arranged on the fixture device, the single-wheeled mobile trolley is driven by the motor to move on the specimen plate, and a strain gauge sensor for testing is provided on the specimen plate. However, this patent document is not applicable to the boundary condition test in the single-point loading compression test. Summary of the invention

[0004] In view of the defects in the prior art, the object of the present invention is to provide a test boundary design method and system for load inverse deduction.

[0005] A test boundary design method for load inverse deduction provided by the present invention comprises the following steps:

[0006] Step 1: Determine the boundary conditions and loading form of the specimen;

[0007] Step 2: designing an initial tooling according to the boundary conditions and the loading form in combination with the interface form of the specimen;

[0008] Step 3: Establish a finite element analysis model structure of the initial tooling, apply force to the specimen, apply the load of the specimen to the initial tooling in reverse, and obtain the deformation structure of the initial tooling through finite element analysis;

[0009] Step 4: According to the deformation structure of the initial tooling and the interface form, the design configuration of the initial tooling is improved to obtain a final tooling applied to the specimen test.

[0010] Preferably, in step 1, the loading form is that the load is applied uniformly.

[0011] Preferably, in step 1, the boundary condition is fixed support or simply supported.

[0012] Preferably, in step 2, the initial tooling cooperates with the test piece interface.

[0013] Preferably, in step 2, the position of the loading point on the initial tooling is clarified.

[0014] Preferably, in step 3, force is applied to the specimen via a loading source and the loading point.

[0015] Preferably, in step 3, the force applied to the force-bearing surface of the specimen is applied in the reverse direction to the force-transmitting surface of the initial tooling.

[0016] Preferably, the force transmission surface of the initial tooling receives a reaction force of equal magnitude and opposite direction from the force bearing surface of the test piece.

[0017] Preferably, the force transmission surface is the mating surface between the initial tooling and the test piece interface.

[0018] The present invention also provides a load-based reverse derivation test boundary design system, comprising the following modules:

[0019] Module M1: Determine the boundary conditions and loading form of the specimen;

[0020] Module M2: designing the initial tooling according to the boundary conditions and the loading form combined with the interface form of the specimen;

[0021] Module M3: Establishing a finite element analysis model structure of the initial tooling, applying force to the specimen, applying the load of the specimen in reverse to the initial tooling, and obtaining the deformation structure of the initial tooling through finite element analysis;

[0022] Module M4: According to the deformation structure of the initial tooling and the interface form, the design configuration of the initial tooling is improved to obtain the final tooling applied to the specimen test.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The method proposed in the present invention is suitable for the application of load with high uniformity requirements, and the test boundary design in the compression test of single-point loading of the tooling can significantly improve and enhance the phenomenon of uneven load application;

[0025] 2. The method of the present invention can be applied to the design of test boundaries for compression tests with single-point loading and high load uniformity;

[0026] 3. The present invention relies on a test boundary design method based on reverse deduction of load, which solves the problem that the load cannot be evenly applied to the specimen in a single-point loading compression test of the specimen, provides a method for more realistic and comprehensive assessment of the specimen structure, and designs tooling boundaries, thereby ensuring the accuracy of the test and the correctness of the test data. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0028] Figure 1 It is a flow chart of the test boundary design method of load reverse deduction of the present invention;

[0029] Figure 2 The schematic diagram of the specimen's loading form, boundary conditions and specimen interface;

[0030] Figure 3 This is the schematic diagram of the initial tooling designed;

[0031] Figure 4 This is a schematic diagram of the initial tooling and test piece assembly;

[0032] Figure 5 It is the schematic diagram of the initial tooling and the force of the specimen;

[0033] Figure 6 Schematic diagram of the initial tooling finite element analysis model established;

[0034] Figure 7 This is the deformation structure diagram of the initial tooling finite element model after being subjected to force;

[0035] Figure 8 This is the final tooling schematic diagram;

[0036] Fig. 9 Schematic diagram of the final tooling and test piece assembly.

[0037] The figure shows:

[0038] Loading point 1 Fixed end 6

[0039] Initial tooling 2 Test piece interface 7

[0040] Reaction force 3 Finite element analysis model structure 8

[0041] Force 4 Initial tooling deformation structure 9

[0042] Test piece 5 Final tooling 10 DETAILED DESCRIPTION

[0043] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0044] Embodiment 1:

[0045] like Figures 1 to 9 As shown, this embodiment provides a test boundary design method for load reverse deduction, including the following steps:

[0046] Step 1: Determine the boundary conditions and loading form of specimen 5. The loading form is uniform load application and the boundary conditions are fixed support or simple support.

[0047] Step 2: According to the boundary conditions and the loading form, the initial tooling 2 is designed in combination with the interface form of the specimen 5. The initial tooling 2 cooperates with the specimen interface 7 to clarify the position of the loading point 1 on the initial tooling 2.

[0048] Step 3: Establish the finite element analysis model structure 8 of the initial tooling 2, apply force to the specimen 5, apply the load of the specimen 5 in reverse to the initial tooling 2, obtain the initial tooling deformation structure 9 through finite element analysis, apply force to the specimen 5 through the loading source and the loading point 1, and reverse the force 4 received by the force-bearing surface of the specimen 5 to the force transmission surface of the initial tooling 2. The force transmission surface of the initial tooling 2 receives a reaction force 3 of equal magnitude and opposite direction from the force-bearing surface of the specimen 5. The force transmission surface is the mating surface between the initial tooling 2 and the specimen interface 7.

[0049] Step 4: According to the initial tooling deformation structure 9 and the interface form, the design configuration of the initial tooling 2 is improved to obtain the final tooling 10 applied to the specimen test.

[0050] Embodiment 2:

[0051] This embodiment provides a test boundary design system for reverse derivation of loads, including the following modules:

[0052] Module M1: Determine the boundary conditions and loading form of specimen 5;

[0053] Module M2: Design the initial tooling 2 according to the boundary conditions and the loading form, combined with the interface form of the specimen 5;

[0054] Module M3: Establish a finite element analysis model structure 8 of the initial tooling 2, apply force to the specimen 5, apply the load of the specimen 5 in reverse to the initial tooling 2, and obtain the initial tooling deformation structure 9 through finite element analysis;

[0055] Module M4: According to the initial tooling deformation structure 9 and the interface form, the design configuration of the initial tooling 2 is improved to obtain the final tooling 10 applied to the test piece 5.

[0056] Embodiment 3:

[0057] Those skilled in the art may understand this embodiment as a more specific description of Embodiment 1 and Embodiment 2.

[0058] This embodiment provides a test boundary design method for load inverse deduction, including the following steps:

[0059] Step S1, determine the boundary conditions and loading form of the specimen. The boundary conditions refer to the fixing method of the specimen, such as fixed support and simple support; the loading form of the specimen refers to the form of load borne by each part of the specimen's force-bearing surface as clearly required in the test. The loading form of the specimen of the present invention is that the load is uniformly applied, that is, the force is uniformly applied to each part of the specimen's force-bearing surface;

[0060] Step S2, design the initial tooling according to the boundary conditions and loading form of the specimen, combined with the shape and size of the interface between the specimen and the tooling. The initial tooling must match the specimen interface, and the location of the loading point must be clearly defined on the initial tooling;

[0061] Step S3, the loading source applies force to the specimen through the loading point on the initial tooling, and the force transmission surface is the mating surface of the initial tooling and the interface of the specimen; if the force requirements of the specimen are to be met, the force transmission surface of the initial tooling will be subjected to a reaction force of equal magnitude and opposite direction from the force-bearing surface of the specimen, and this force is the force that the force-bearing surface of the specimen is subjected to as required by the test;

[0062] Step S4, establishing a finite element analysis model of the initial tooling, and applying the force received by the force-bearing surface of the specimen in reverse to the force-transmitting surface of the initial tooling;

[0063] Step S5, obtaining a deformation structure diagram of the initial tooling through finite element analysis;

[0064] Step S6, based on the initial tooling deformation structure diagram and the test piece interface obtained by finite element analysis, the design configuration of the initial tooling is improved to obtain the final tooling applied to the test piece test.

[0065] The above method requires that the force on the specimen's force-bearing surface be reversed to the force-transmitting surface of the initial tooling. The above method requires that the deformation of the initial tooling after the force-transmitting surface of the initial tooling is subjected to the reaction force from the specimen's force-bearing surface be analyzed by establishing a finite element analysis model of the initial tooling, and the deformation structure diagram of the initial tooling be obtained. The above method designs a new tooling for the specimen test based on the deformation structure diagram after the finite element analysis of the initial tooling and the specimen interface.

[0066] Embodiment 4:

[0067] Those skilled in the art may understand this embodiment as a more specific description of Embodiment 1 and Embodiment 2.

[0068] The present invention provides a test boundary design method for load reverse deduction, specifically:

[0069] In the single-point loading compression test, in order to meet the loading uniformity requirements, the initial tooling is designed according to the boundary conditions, loading form and interface of the specimen. The initial tooling is required to cooperate with the interface of the specimen and clearly define the location of the loading point.

[0070] The initial tooling cannot satisfy the requirement of uniform stress on the specimen under single-point loading conditions, so the initial tooling needs to be optimized and improved to further meet the test conditions.

[0071] The loading source applies force to the specimen through the loading point on the initial tooling. At the same time, the force transmission surface of the initial tooling will receive a reaction force of equal magnitude and opposite direction from the force-bearing surface of the specimen. The force transmission surface mentioned here is the mating surface between the initial tooling and the specimen interface, and the action force is the force required by the test to be received by the force-bearing surface of the specimen.

[0072] In order to optimize the test boundary conditions, the finite element analysis model of the initial tooling was established, and the force on the force-bearing surface of the specimen was reversed to the force-transmitting surface of the initial tooling.

[0073] After finite element analysis, the deformation structure diagram of the initial tooling was obtained.

[0074] According to the deformation structure diagram of the initial tooling and the specimen interface obtained by finite element analysis, the design configuration of the initial tooling was improved to obtain the final tooling used for the specimen test.

[0075] The above method takes into account the deformation of the initial tooling during the loading process in advance, optimizes and improves the test boundary of the initial tooling, and designs the final tooling. In the entire single-point loading compression test, it is ensured that the force can be evenly applied to the stress surface of the specimen through the final tooling, ensuring that the specimen is evenly stressed during the entire test process.

[0076] The present embodiment provides a method for designing a test boundary by reverse deduction of load, which can be applied to the design of test boundaries for compression tests with single-point loading and high load uniformity. The technical solution of the present embodiment is to optimize the test boundary design based on finite element analysis. The present invention can achieve uniform loading of the test piece in a single-point loading compression test.

[0077] Embodiment 5:

[0078] Those skilled in the art may understand this embodiment as a more specific description of Embodiment 1 and Embodiment 2.

[0079] The present embodiment provides a test boundary design method by reverse deduction of load: first, the load form and boundary conditions of the specimen are clarified; second, the initial tooling is designed in combination with the interface form of the specimen; then, a finite element analysis model structure of the initial tooling is established, and the load of the specimen is reversely applied to the initial tooling, and the deformation structure of the initial tooling is obtained through finite element analysis; finally, in combination with the interface form of the specimen, the configuration of the initial tooling after finite element analysis deformation is used as an improved design configuration to design a new tooling interface.

[0080] like Figure 2 As shown, the loading form refers to the uniform force on the upper end of the specimen, i.e., the applied force 4, the boundary condition refers to the fixed support of the fixed end 6 at the lower end of the specimen 5, and the specimen interface 7 refers to the shape of the upper end of the specimen 5, i.e., the force-bearing end. The initial tooling 2 designed according to the loading form, boundary conditions and specimen interface 7 of the specimen 5 is as follows: Figure 3 As shown, the position of the loading point 1 is at the center of the upper end surface of the initial tooling 2, which is a single-point loading.

[0081] Figure 4 It is an assembly diagram of the designed initial tooling 2 and the test piece 5. The initial tooling 2 and the test piece interface 7 must meet the matching requirements.

[0082] In order to meet the force requirements of the specimen 5, the force transmission surface of the initial tooling 2 needs to be subjected to a reaction force 3 of equal magnitude and opposite direction from the force surface of the specimen 5, that is, the force 4 on the force surface of the specimen 5 required by the test is as follows: Figure 5 shown.

[0083] A finite element analysis model structure 8 of the initial tooling 2 is established. According to the force form of the initial tooling 2, the reaction force 3 is applied to the initial tooling 2 for finite element analysis, such as Figure 6 shown.

[0084] The initial tooling deformation structure 9 can be obtained, such as Figure 7 shown.

[0085] According to the initial tooling deformation structure 9, the final tooling 10 is designed for the experiment, and the position of the loading point 1 is at the center of the upper end of the final tooling 10, as shown in FIG. Figure 8 shown.

[0086] The final tooling 10 is assembled with the test piece 5 and tested. Fig. 9 shown.

[0087] By utilizing the test boundary design method proposed in this embodiment, uniform loading of the test piece in a single-point compression test can be achieved.

[0088] The method proposed in the present invention is suitable for the requirements on uniformity of load application, and through the test boundary design in the compression test of single-point loading of the tooling, the phenomenon of uneven load application is significantly improved and enhanced.

[0089] Those skilled in the art know that, in addition to realizing the system and its various devices, modules, and units provided by the present invention in a purely computer-readable program code, it is entirely possible to realize the same functions in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system and its various devices, modules, and units provided by the present invention can be considered as a hardware component, and the devices, modules, and units included therein for realizing various functions can also be regarded as structures within the hardware component; the devices, modules, and units for realizing various functions can also be regarded as both software modules for realizing the method and structures within the hardware component.

[0090] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A test boundary design method for load inverse deduction, characterized in that: The steps include: Step 1: Determine the boundary conditions and loading form of the specimen (5); Step 2: designing an initial tooling (2) according to the boundary conditions and the loading form and in combination with the interface form of the test piece (5); Step 3: Establishing a finite element analysis model structure (8) of the initial tooling (2), applying force to the test piece (5), applying the load of the test piece (5) in reverse to the initial tooling (2), and obtaining the initial tooling deformation structure (9) through finite element analysis; Step 4: improving the design configuration of the initial tooling (2) according to the initial tooling deformation structure (9) and the interface form, and obtaining a final tooling (10) applied to the specimen test; In the step 1, the load is applied uniformly; In the step 1, the boundary condition is fixed support or simply supported; In the step 2, the initial tooling (2) is matched with the test piece interface (7); In the step 2, the position of the loading point (1) on the initial tooling (2) is determined.

2. The test boundary design method of load inverse deduction according to claim 1 is characterized in that: In the step 3, a force is applied to the test piece (5) via the loading source and the loading point (1).

3. The test boundary design method of load inverse deduction according to claim 2 is characterized in that: In the step 3, the force (4) applied to the force-bearing surface of the test piece (5) is applied in the reverse direction to the force-transmitting surface of the initial tooling (2).

4. The test boundary design method of load inverse deduction according to claim 3 is characterized in that: The force transmission surface of the initial tooling (2) is subjected to a reaction force (3) of equal magnitude and opposite direction from the force receiving surface of the test piece (5).

5. The test boundary design method of load inverse deduction according to claim 4 is characterized in that: The force transmission surface is the matching surface between the initial tooling (2) and the test piece interface (7).

Images