Statically indeterminate constraint support clamp rigidity optimization method and system

Abstract

The invention belongs to the field of aviation structure design, and particularly relates to a statically indeterminate constraint support clamp rigidity optimization method and system. Comprising the following steps: S1, determining a rigidity variable, a load target value and an optimization target of each constraint point on the statically indeterminate support fixture; s2, establishing a finite element model comprising a test piece and a statically indeterminate support clamp, and applying rigidity constraint and a test load on the finite element model; s3, carrying out finite element solution to obtain a load calculation value of each constraint point; s4, the load calculation value and the load target value are compared and analyzed, a comparison result is calculated, and whether the comparison result meets an optimization target or not is judged; and if the comparison result does not meet the optimization target, adjusting the rigidity of each constraint point, returning to the step S3, carrying out loop iteration until the comparison result meets the optimization target, and outputting the rigidity distribution of each constraint point. According to the method, the rigidity distribution of the statically indeterminate support clamp can be obtained, and support is provided for design of the statically indeterminate support clamp.

Description

Technical Field

[0001] The present application belongs to the field of aviation structure design, and in particular relates to a method and system for optimizing the stiffness of an over-statically-determined constraint support fixture. Background Art

[0002] Hyperstatic support fixtures have many influencing factors and are difficult to design. Due to lack of design experience, the stiffness of the overall docking structure is difficult to match the test requirements, which is a difficult point in the test design.

[0003] In the prior art, the statically indeterminate test fixture usually adopts a real docking structure, which has the disadvantages of being large in scale and high in cost, and is not conducive to the control of test cost.

[0004] Therefore, it is desired to have a technical solution to overcome or at least alleviate at least one of the above-mentioned defects of the prior art. Summary of the invention

[0005] The purpose of the present application is to provide a method and system for optimizing the stiffness of an over-statically-determined constraint-supported fixture to solve at least one problem existing in the prior art.

[0006] The technical solution of this application is:

[0007] A first aspect of the present application provides a method for optimizing stiffness of an over-statically-determined constraint-supported fixture, comprising:

[0008] Step S1, determining the stiffness variable, load target value and optimization target of each constraint point on the hyperstatic support fixture;

[0009] Step S2, establishing a finite element model including the test piece and the statically indeterminate support fixture, and applying stiffness constraints and test loads to the finite element model;

[0010] Step S3, performing finite element solution to obtain the load calculation value of each constraint point;

[0011] Step S4: Compare and analyze the calculated load value with the target load value, calculate the comparison result, and determine whether the comparison result meets the optimization goal;

[0012] If not, adjust the stiffness of each constraint point and return to step S3 to iterate until the comparison result meets the optimization goal, and output the stiffness distribution of each constraint point.

[0013] In at least one embodiment of the present application, in step S1 , the stiffness variables of each constraint point include heading stiffness, vertical stiffness, and out-of-plane stiffness.

[0014] In at least one embodiment of the present application, in step S1, the load target value of each constraint point includes a heading load target value, a vertical load target value, and an out-of-plane load target value.

[0015] In at least one embodiment of the present application, in step S1, the optimization target of each constraint point is that the mean square error between the load calculation value and the load target value does not exceed a first threshold.

[0016] In at least one embodiment of the present application, in step S1, the optimization target of each constraint point is that the difference percentage between the load calculation value and the load target value does not exceed a second threshold.

[0017] In at least one embodiment of the present application, in step S3, NASTRAN is used to perform linear finite element solution.

[0018] In at least one embodiment of the present application, in step S3, the calculated load value of each constraint point includes a calculated heading load value, a calculated vertical load value, and a calculated out-of-plane load value.

[0019] In at least one embodiment of the present application, step S4, adjusting the stiffness of each constraint point, includes:

[0020] Adjust the axial stiffness, vertical stiffness and / or out-of-plane stiffness of each constraint point.

[0021] A second aspect of the present application provides a hyperstatic constraint support fixture stiffness optimization system, comprising:

[0022] The initial setup module is used to determine the stiffness variables, load target values, and optimization targets of each constraint point on the statically indeterminate support fixture;

[0023] The finite element model building module is used to build a finite element model including the test piece and the hyperstatic support fixture, and to apply stiffness constraints and test loads on the finite element model;

[0024] Finite element solution module, used to perform finite element solution and obtain the load calculation value of each constraint point;

[0025] The loop iteration module is used to compare and analyze the load calculation value with the load target value, calculate the comparison result, and determine whether the comparison result meets the optimization goal;

[0026] If not, adjust the stiffness of each constraint point, return to the finite element solution module, iterate repeatedly until the comparison result meets the optimization goal, and output the stiffness distribution of each constraint point.

[0027] The third aspect of the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that when the processor executes the computer program, the hyperstatic constraint supported fixture stiffness optimization method as described above is implemented.

[0028] The fourth aspect of the present application provides a computer-readable storage medium, which stores a computer program, characterized in that when the computer program is executed by a processor, it can implement the hyperstatic constraint support fixture stiffness optimization method as described above.

[0029] The invention has at least the following beneficial technical effects:

[0030] The hyperstatic constraint support fixture stiffness optimization method of the present application can obtain the stiffness distribution of the hyperstatic support fixture, providing support for the design of the hyperstatic support fixture. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a flow chart of optimization of stiffness of an over-statically-determined constraint-supported fixture according to one embodiment of the present application. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the embodiment of this application will be described in more detail below in conjunction with the drawings in the embodiment of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of this application, not all of them. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain this application, and should not be construed as limitations on this application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The embodiments of this application are described in detail below in conjunction with the drawings.

[0033] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present application.

[0034] The following is combined with Figure 1 This application is described in further detail.

[0035] The first aspect of the present application provides a method for optimizing stiffness of an over-statically-determined constraint-supported fixture, comprising the following steps:

[0036] Step S1, determining the stiffness variable, load target value and optimization target of each constraint point on the hyperstatic support fixture;

[0037] Step S2, establishing a finite element model including the test piece and the hyperstatic support fixture, and applying stiffness constraints and test loads to the finite element model;

[0038] Step S3, performing finite element solution to obtain the load calculation value of each constraint point;

[0039] Step S4: Compare and analyze the calculated load value with the target load value, calculate the comparison result, and determine whether the comparison result meets the optimization goal;

[0040] If not, adjust the stiffness of each constraint point and return to step S3 to iterate until the comparison result meets the optimization goal, and output the stiffness distribution of each constraint point.

[0041] The hyperstatic constraint support fixture stiffness optimization method of the present application, first, in step S1, initial settings are performed, including determining the stiffness variables, load target values ​​and optimization targets of each constraint point on the hyperstatic support fixture. In a preferred embodiment of the present application, each constraint point corresponds to three stiffness variables, including heading stiffness, vertical stiffness and out-of-plane stiffness. The load target value of each constraint point includes a heading load target value, a vertical load target value and an out-of-plane load target value. The optimization target of each constraint point can be determined based on the load calculation value and the load target value. For example, in one embodiment of the present application, the optimization target of each constraint point is that the mean square error of the load calculation value and the load target value does not exceed a first threshold. In another embodiment of the present application, the optimization target of each constraint point is that the percentage difference between the load calculation value and the load target value does not exceed a second threshold.

[0042] In the hyperstatic constraint support fixture stiffness optimization method of the present application, in step S3, NASTRAN is preferably used for linear finite element solution to obtain a result file containing load calculation value information of each constraint point. The load calculation value of each constraint point includes a directional load calculation value, a vertical load calculation value, and an out-of-plane load calculation value.

[0043] Further, in step S4, the calculated load value of each constraint point obtained in step S3 is calculated with the corresponding load target value, and the mean square error is calculated to determine whether the mean square error of the calculated load value and the load target value does not exceed the first threshold value; or the difference percentage is calculated to determine whether the difference percentage of the calculated load value and the load target value does not exceed the second threshold value. When the calculated comparison result does not meet the optimization target, the heading stiffness, vertical stiffness and / or out-of-plane stiffness of each constraint point are adjusted, and then the process returns to step S3, iterates in a loop until the comparison result meets the optimization target, and the stiffness distribution of each constraint point is output.

[0044] The hyperstatic constraint support fixture stiffness optimization method of the present application uses the finite element calculation method to obtain the stiffness data of the hyperstatic support fixture under specific loads and structural forms, providing support for the design of the support fixture, improving the test fixture design capability, and saving test funds.

[0045] Based on the above-mentioned statically indeterminate constraint support fixture stiffness optimization method, the second aspect of the present application provides a statically indeterminate constraint support fixture stiffness optimization system, comprising:

[0046] The initial setup module is used to determine the stiffness variables, load target values, and optimization targets of each constraint point on the statically indeterminate support fixture;

[0047] The finite element model building module is used to build a finite element model including the test piece and the hyperstatic support fixture, and to apply stiffness constraints and test loads on the finite element model;

[0048] Finite element solution module, used to perform finite element solution and obtain the load calculation value of each constraint point;

[0049] The loop iteration module is used to compare and analyze the load calculation value with the load target value, calculate the comparison result, and determine whether the comparison result meets the optimization goal;

[0050] If not, adjust the stiffness of each constraint point, return to the finite element solution module, iterate repeatedly until the comparison result meets the optimization goal, and output the stiffness distribution of each constraint point.

[0051] The hyperstatic constraint support fixture stiffness optimization system of the present application records the optimization variables, optimization targets and optimization termination conditions through the initial setting module, establishes a finite element model including the test piece and the hyperstatic support fixture through the finite element model establishment module, and uses NASTRAN to perform linear finite element calculations through the finite element solution module to obtain the result file of the load calculation value information of each constraint point. The loop iteration module includes a stiffness adjustment unit and a loop iteration unit. The stiffness adjustment unit calculates the comparison result between the load calculation value and the load target value, and compares it with the optimization target to determine whether to adjust the stiffness of each constraint point and whether to enter the loop iteration; the loop iteration unit corrects the finite element model file based on the stiffness adjustment file, and the finite element solution module re-obtains the load calculation value information of each constraint point, and iterates until the load of each constraint point meets the optimization target.

[0052] The third aspect of the present application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor, and when the processor executes the computer program, the above-mentioned hyperstatic constraint-supported fixture stiffness optimization method is implemented.

[0053] The fourth aspect of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it can implement the above-mentioned hyperstatic constraint support fixture stiffness optimization method.

[0054] It is understandable that the computer program mainly consists of two parts: calling the NASTRAN linear calculation program and the Python support fixture stiffness optimization program. Using this optimization method, the comparison of linear analysis constraint point load results can be achieved, the fixture stiffness can be automatically revised, and iterative calculations can be completed. The algorithm automatically searches for the optimal fixture stiffness solution under the user-specified load conditions, greatly reducing the workload of designers, providing data support for the design of supporting fixtures, improving the design capabilities of test fixtures, and saving test funds.

[0055] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for optimizing the stiffness of an indeterminate constraint support fixture, characterized in that: include: Step S1, determining the stiffness variable, load target value and optimization target of each constraint point on the hyperstatic support fixture; Step S2, establishing a finite element model including the test piece and the statically indeterminate support fixture, and applying stiffness constraints and test loads to the finite element model; Step S3, performing finite element solution to obtain the load calculation value of each constraint point; Step S4: Compare and analyze the calculated load value with the target load value, calculate the comparison result, and determine whether the comparison result meets the optimization goal; If not, adjust the stiffness of each constraint point and return to step S3 to iterate until the comparison result meets the optimization goal, and output the stiffness distribution of each constraint point.

2. The method for optimizing stiffness of a statically indeterminate constraint support fixture according to claim 1, characterized in that: In step S1, the stiffness variables of each constraint point include heading stiffness, vertical stiffness and out-of-plane stiffness.

3. The method for optimizing stiffness of an over-statically-determined constraint support fixture according to claim 2, characterized in that: In step S1, the load target value of each constraint point includes a heading load target value, a vertical load target value and an out-of-plane load target value.

4. The method for optimizing stiffness of an over-statically-determined constraint support fixture according to claim 3, characterized in that: In step S1, the optimization target of each constraint point is that the mean square error between the load calculation value and the load target value does not exceed a first threshold.

5. The method for optimizing stiffness of an over-statically-determined constraint support fixture according to claim 3, characterized in that: In step S1, the optimization target of each constraint point is that the difference percentage between the load calculation value and the load target value does not exceed the second threshold value.

6. The method for optimizing stiffness of an over-statically-determined constraint support fixture according to claim 4 or 5, characterized in that: In step S3, NASTRAN is used to perform linear finite element solution.

7. The method for optimizing stiffness of an over-statically-determined constraint support fixture according to claim 6, characterized in that: In step S3, the load calculation value of each constraint point includes a heading load calculation value, a vertical load calculation value, and an out-of-plane load calculation value.

8. The method for optimizing stiffness of an over-statically-determined constraint support fixture according to claim 7, characterized in that: Step S4, adjusting the stiffness of each constraint point, including: Adjust the axial stiffness, vertical stiffness and / or out-of-plane stiffness of each constraint point.

9. An over-statically-determined constraint support fixture stiffness optimization system, characterized in that: include: The initial setup module is used to determine the stiffness variables, load target values, and optimization targets of each constraint point on the statically indeterminate support fixture; The finite element model building module is used to build a finite element model including the test piece and the hyperstatic support fixture, and to apply stiffness constraints and test loads on the finite element model; Finite element solution module, used to perform finite element solution and obtain the load calculation value of each constraint point; The loop iteration module is used to compare and analyze the load calculation value with the load target value, calculate the comparison result, and determine whether the comparison result meets the optimization goal; If not, adjust the stiffness of each constraint point, return to the finite element solution module, iterate repeatedly until the comparison result meets the optimization goal, and output the stiffness distribution of each constraint point.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that: When the processor executes the computer program, the method for optimizing the stiffness of an over-statically-determined constraint-supported fixture as claimed in any one of claims 1 to 8 is implemented.

11. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, it is capable of implementing the hyperstatic constraint support fixture stiffness optimization method as described in any one of claims 1 to 8.

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