Fatigue simulation method, device and equipment for rear trailer hook and readable storage medium

Abstract

The invention discloses a rear trailer hook fatigue simulation method, device and equipment and a readable storage medium, and the method comprises the steps: building a finite element simulation model of a rear trailer hook based on the design three-dimensional data of the rear trailer hook and a body in white; performing punch forming simulation on all or part of the sheet metal parts to obtain punch forming simulation data of the plurality of sheet metal parts; in the finite element simulation model, the punch forming simulation data of the multiple sheet metal parts are used for replacing initial data of the corresponding parts, strength simulation of the single push-pull cycle working condition is carried out on the rear trailer hook, and stress data of all the parts are obtained; and based on the stress data of each part, performing fatigue simulation on the rear trailer hook to obtain the durable damage and fatigue life of each part. According to the method and the device, the punch forming simulation data of all or part of sheet metal parts in the rear trailer hook and the body-in-white on which the rear trailer hook is mounted are added into fatigue simulation analysis, so that the accuracy of fatigue simulation of the rear trailer hook and the body-in-white mounting point of the rear trailer hook can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of fatigue simulation, and in particular to a method, device, equipment and readable storage medium for fatigue simulation of a rear trailer hook. Background Art

[0002] For a passenger car towing a RV, during the process of towing the RV, the rear trailer hook installation point needs to bear various loads from the RV. If the fatigue performance is insufficient, structural damage will cause the towing device to fail or even cause a safety accident. Therefore, fatigue simulation of the towing structure is required in the early design stage, and fatigue testing of the towing structure is required in the trial production stage to ensure that the product has qualified towing qualifications when it enters the market.

[0003] However, the fatigue simulation of the rear trailer hook in the early design stage is not accurate enough, resulting in the fatigue problems of the actual vehicle not being fully exposed during the simulation. Summary of the invention

[0004] The present application provides a rear trailer hook fatigue simulation method, device, equipment and readable storage medium, aiming to solve the technical problem that the fatigue simulation of the rear trailer hook is not accurate enough in the early design stage, resulting in the fatigue problem of the actual vehicle not being fully exposed during the simulation.

[0005] In a first aspect, an embodiment of the present application provides a rear trailer hook fatigue simulation method, the rear trailer hook fatigue simulation method comprising:

[0006] Based on the design three-dimensional data of the rear trailer hook and the body-in-white, a finite element simulation model of the rear trailer hook is established, wherein the rear trailer hook is installed on the body-in-white, and both the rear trailer hook and the body-in-white include multiple parts, and the multiple parts include sheet metal parts;

[0007] Perform stamping simulation on all or part of the sheet metal parts to obtain stamping simulation data of multiple sheet metal parts;

[0008] In the finite element simulation model, the stamping simulation data of multiple sheet metal parts are used to replace the initial data of the corresponding parts, and the strength simulation of a single push-pull cycle working condition of the rear trailer hook is performed to obtain the stress data of each part;

[0009] Based on the stress data of each part, fatigue simulation of the rear trailer hook is carried out to obtain the durable damage and fatigue life of each part.

[0010] Optionally, establishing a finite element simulation model of the rear trailer hook based on the design three-dimensional data of the rear trailer hook and the body-in-white includes:

[0011] Based on the design 3D data of the rear trailer hook and the body-in-white, the rear trailer hook and the body-in-white are meshed, connections are established for each part, constraints are set for each connected part, and a finite element simulation model of the rear trailer hook is obtained.

[0012] Optionally, before performing stamping simulation on all or part of the sheet metal parts to obtain stamping simulation data of multiple sheet metal parts, the method includes:

[0013] In the finite element simulation model, the initial strength of the rear trailer hook is simulated under a single push-pull cycle to obtain the initial stress data of each part;

[0014] Based on the initial stress data of each part, a first preset number of sheet metal parts having stresses in descending order are selected from each part to obtain a first sheet metal part;

[0015] Selecting a second preset number of sheet metal parts with decreasing feature sharpness from the first sheet metal part to obtain a second sheet metal part;

[0016] The second sheet metal part is determined as a partial part for stamping simulation.

[0017] Optionally, the step of replacing initial data of corresponding parts with the stamping simulation data of the plurality of sheet metal parts comprises:

[0018] The material thickness simulation distribution, residual stress and plastic strain in the stamping simulation data of multiple sheet metal parts are used to replace the initial distribution of material thickness, initial stress and initial strain in the initial data of the corresponding parts.

[0019] Optionally, the fatigue simulation of the rear trailer hook is performed based on the stress data of each component to obtain the durable damage and fatigue life of each component, including:

[0020] For each sheet metal part subjected to stamping simulation, the residual stress in the stamping simulation data is used as the initial stress of the sheet metal part;

[0021] For each part, the average stress and stress amplitude of the part are calculated based on the maximum stress and minimum stress under the strength simulation of a single push-pull cycle;

[0022] Using the average stress of the part, the Morlot equation is used to correct the material stress-life curve equation of the part to obtain the corrected stress-life curve equation;

[0023] Substitute the stress amplitude of the part into the modified stress-life curve equation to calculate the fatigue life of the part;

[0024] Based on the fatigue life of the parts, the durable damage of the parts is calculated.

[0025] Optionally, the strength simulation of a single push-pull cycle working condition of the rear trailer hook includes:

[0026] The vehicle is unloaded after applying a preset pulling force of a first preset angle to the ball head of the rear trailer hook, and the vehicle is unloaded after applying a preset thrust of a second preset angle to the ball head of the rear trailer hook.

[0027] In a second aspect, an embodiment of the present application provides a rear trailer hook fatigue simulation device, the rear trailer hook fatigue simulation device comprising:

[0028] A model building module is used to build a finite element simulation model of the rear trailer hook based on the design three-dimensional data of the rear trailer hook and the body-in-white, wherein the rear trailer hook is installed on the body-in-white, and the rear trailer hook and the body-in-white both include multiple parts, and the multiple parts include sheet metal parts;

[0029] A stamping simulation module is used to perform stamping simulation on all or part of the sheet metal parts to obtain stamping simulation data of multiple sheet metal parts;

[0030] Strength simulation module, used to replace the initial data of corresponding parts with the stamping simulation data of multiple sheet metal parts in the finite element simulation model, perform strength simulation of a single push-pull cycle on the rear trailer hook, and obtain stress data of each part;

[0031] The fatigue simulation module is used to perform fatigue simulation on the rear trailer hook based on the stress data of each part to obtain the durable damage and fatigue life of each part.

[0032] Optionally, the model building module is used to:

[0033] Based on the design 3D data of the rear trailer hook and the body-in-white, the rear trailer hook and the body-in-white are meshed, connections are established for each part, constraints are set for each connected part, and a finite element simulation model of the rear trailer hook is obtained.

[0034] In the third aspect, an embodiment of the present application provides a rear trailer hook fatigue simulation device, which includes a processor, a memory, and a rear trailer hook fatigue simulation program stored in the memory and executable by the processor, wherein when the rear trailer hook fatigue simulation program is executed by the processor, the steps of the rear trailer hook fatigue simulation method as described above are implemented.

[0035] In a fourth aspect, an embodiment of the present application provides a readable storage medium, on which a rear trailer hook fatigue simulation program is stored, wherein when the rear trailer hook fatigue simulation program is executed by a processor, the steps of the rear trailer hook fatigue simulation method as described above are implemented.

[0036] The beneficial effects brought by the technical solution provided in the embodiments of the present application include:

[0037] In an embodiment of the present application, a finite element simulation model of the rear trailer hook is established based on the design three-dimensional data of the rear trailer hook and the body-in-white, wherein the rear trailer hook is installed on the body-in-white, and the rear trailer hook and the body-in-white both include multiple parts, and the multiple parts include sheet metal parts; stamping simulation is performed on all or part of the sheet metal parts to obtain stamping simulation data of multiple sheet metal parts; in the finite element simulation model, the stamping simulation data of multiple sheet metal parts are used to replace the initial data of the corresponding parts, and the strength simulation of a single push-pull cycle working condition is performed on the rear trailer hook to obtain stress data of each part; based on the stress data of each part, fatigue simulation is performed on the rear trailer hook to obtain durable damage and fatigue life of each part. In the embodiments of the present application, the current finite element simulation model does not take into account the impact of stamping and forming of sheet metal parts in the rear trailer hook and the body-in-white on which it is installed, or only takes into account ideal conditions. For example, the material thickness distribution in the sheet metal parts is set to a uniform state, and ideal stress and strain data of the material are adopted. However, the thickness distribution of the sheet metal parts will change after actual stamping and forming, and residual stress and plastic strain will also exist. In addition, the material thickness distribution, residual stress and plastic strain will have a great influence on the fatigue simulation analysis results of the rear trailer hook, resulting in the current finite element simulation model being not accurate enough for the fatigue simulation of the rear trailer hook. The present application improves the accuracy of the fatigue simulation of the rear trailer hook and its body mounting points by adding the stamping simulation data of all or part of the sheet metal parts in the rear trailer hook and the body-in-white on which it is installed to the fatigue simulation analysis of the finite element model, so that the fatigue problems of the actual vehicle in the later stage can be fully exposed in the simulation stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a flow chart of an embodiment of a method for simulating fatigue of a rear trailer hook of the present application;

[0039] Figure 2 A schematic diagram of a single push-pull cycle working condition of a rear trailer hook and a body-in-white according to an embodiment of a fatigue simulation method for a rear trailer hook of the present application;

[0040] Figure 3 For this application Figure 1 A detailed flow chart of step S40;

[0041] Figure 4 A schematic diagram of a stress history curve of an embodiment of a fatigue simulation method for a rear trailer hook of the present application;

[0042] Figure 5 This is a functional module diagram of an embodiment of a rear trailer hook fatigue simulation device of the present application;

[0043] Figure 6This is a schematic diagram of the hardware structure of the rear trailer hook fatigue simulation device involved in the embodiment of the present application. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0045] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0046] In a first aspect, an embodiment of the present application provides a rear trailer hook fatigue simulation method.

[0047] In one embodiment, referring to Figure 1 , Figure 1 This is a flow chart of an embodiment of a method for simulating fatigue of a rear trailer hook according to the present application. Figure 1 As shown in the figure, the fatigue simulation method of the rear trailer hook includes:

[0048] Step S10, based on the design three-dimensional data of the rear trailer hook and the body-in-white, a finite element simulation model of the rear trailer hook is established, wherein the rear trailer hook is installed on the body-in-white, and the rear trailer hook and the body-in-white both include multiple parts, and the multiple parts include sheet metal parts.

[0049] In this embodiment, the design 3D data of the body-in-white and the rear tow hook crossbeam assembly can be imported into the finite element analysis pre-processing software Hypermesh, the sheet metal parts can be meshed using 2D units, the rear tow hook body can be meshed using 3D units, the attributes and material information can be set according to the actual vehicle status, and connections can be established for each part. Constraints can be set for each connected part to obtain a finite element simulation model of the rear tow hook. Among them, the rear tow hook is a traction structure installed on the body-in-white. The body-in-white refers to the body that has been welded but not yet painted. Since the body-in-white and the rear tow hook are connected, it will also be subjected to stress. Therefore, the installation point of the rear tow hook on the body-in-white and some key stress-bearing parts on the body-in-white are also the focus of the fatigue simulation analysis of the rear tow hook. In order to improve efficiency, the front half of the body-in-white that is not the focus of attention can be cut off, and only the rear half of the body-in-white can be retained. For reference, Figure 2 , Figure 2 This is a schematic diagram of a single push-pull cycle of the rear trailer hook and the body-in-white according to an embodiment of the fatigue simulation method for the rear trailer hook of the present application. Figure 2As shown, the rear trailer hook and the body-in-white each include a plurality of parts, including sheet metal parts, wherein the sheet metal parts refer to parts obtained by using sheet metal materials through a stamping and forming process.

[0050] Step S20, performing stamping simulation on all or part of the sheet metal parts to obtain stamping simulation data of a plurality of sheet metal parts.

[0051] In this embodiment, the current finite element simulation model does not take into account the impact of stamping and forming of sheet metal parts in the rear trailer hook and the body-in-white on which it is installed, or takes ideal conditions into consideration. For example, the material thickness distribution in the sheet metal parts is set to a uniform state, and ideal stress and strain data of the material are adopted. However, the thickness distribution of the sheet metal parts will change after actual stamping and forming, and residual stress and plastic strain will also exist. In addition, the material thickness distribution, residual stress and plastic strain will have a significant impact on the fatigue simulation analysis results of the rear trailer hook, resulting in the current finite element simulation model being not accurate enough for the fatigue simulation of the rear trailer hook. Therefore, in this embodiment, stamping and forming simulation is first performed on all or part of the sheet metal parts of the rear trailer hook and the body-in-white to obtain stamping and forming simulation data of multiple sheet metal parts. Specifically, each sheet metal part that needs to be simulated for stamping can be imported into the autoform software (a digital planning and verification software for metal sheet forming processes and parts), and the blank holder and punch can be selected and necessary settings can be made, such as setting the material thickness and offset direction, etc. According to the specific stamping requirements, the parameters for simulated stamping can be set. The autoform software will automatically simulate the stamping process of sheet metal materials, calculate and output the material thickness distribution, residual stress and plastic strain of each sheet metal part after stamping, and save the output results in .dyn file format.

[0052] Step S30, in the finite element simulation model, the stamping simulation data of multiple sheet metal parts are used to replace the initial data of the corresponding parts, and the strength simulation of a single push-pull cycle working condition of the rear trailer hook is performed to obtain the stress data of each part.

[0053] In this embodiment, the material thickness distribution, residual stress and plastic strain of each sheet metal part after stamping in the .dyn file format obtained in step S20 are imported into the ANSA finite element simulation software, and the stamping simulation data of multiple sheet metal parts are used to replace the initial data of the corresponding parts. Specifically, the Results Mapper tool in the Analysis Tool drop-down menu in the ANSA software is used to map to the stress calculation model, and the source model format is set to dyna in the source module and the material thickness distribution, residual stress and plastic strain of each sheet metal part after stamping in the .dyn file format obtained in step S20 are imported through the file selection button, and then the content to be mapped is checked in the Mappings module, and finally the part Property that needs to introduce the forming result in the stress calculation model is selected in the Mapping Options, and the mapping of the stamping simulation result to the stress calculation model is completed by clicking OK. Further, the initial conditions of the model after mapping can be viewed in Fringe in the view menu, and the initial stress results can be checked to see whether the initial stress results are normal, whether the cloud map is smooth, and whether the thickness of the material changes according to the forming simulation results. If there is no abnormality, the mapping is successful, and the thickness and stress strain state of the part after forming have been set as the initial conditions of the model. Then, a single push-pull cycle strength simulation is performed on the rear trailer hook, that is, a preset pulling force of a first preset angle is applied to the ball head of the rear trailer hook and then the tension is unloaded, and a preset thrust force of a second preset angle is applied to the ball head of the rear trailer hook and then the tension is unloaded. The stress data of each part under the single push-pull cycle strength simulation considering the influence of stamping forming is obtained for subsequent fatigue simulation analysis.

[0054] Step S40, based on the stress data of each component, fatigue simulation is performed on the rear trailer hook to obtain the durable damage and fatigue life of each component.

[0055] In this embodiment, the stress data of each part under the single push-pull cycle working condition strength simulation is imported into the FEMFAT fatigue simulation calculation software, wherein the single push-pull cycle working condition strength simulation includes four load steps, namely, applying a preset tension of a first preset angle to the ball head of the rear trailer hook and then unloading, applying a preset thrust of a second preset angle to the ball head of the rear trailer hook and then unloading, and the TransMAX module in the FEMFAT software is used to construct the stress cycle history of the part, and the material SN curve (i.e., stress-life curve) is assigned to the part according to the design material, and the average stress influence and statistical influence are activated in the influencing factors, and the durable damage and fatigue life of the part are calculated and output. Furthermore, the result of the fatigue simulation can be judged whether it is qualified in combination with the goal of the fatigue simulation.

[0056] In this embodiment, the current finite element simulation model does not take into account the impact of stamping forming of the sheet metal parts in the rear trailer hook and the body-in-white on which it is installed, or only takes into account ideal conditions. For example, the material thickness distribution in the sheet metal parts is set to a uniform state, and ideal stress and strain data of the material are used. However, the thickness distribution of the sheet metal parts will change after actual stamping forming, and residual stress and plastic strain will also exist. In addition, the material thickness distribution, residual stress and plastic strain will have a significant impact on the fatigue simulation analysis results of the rear trailer hook, resulting in the current finite element simulation model being not accurate enough for the fatigue simulation of the rear trailer hook. Therefore, in this embodiment, by importing the design 3D data of the body-in-white and the rear tow hook crossbeam assembly into the finite element analysis pre-processing software Hypermesh, the sheet metal parts are meshed using 2D units, the rear tow hook body is meshed using 3D units, the attributes and material information are set according to the actual vehicle state, and connections are established for each part. Constraints are set for each connected part to obtain a finite element simulation model of the rear tow hook, and each sheet metal part that needs to be stamped and formed is imported into the autoform software respectively. The autoform software will automatically simulate the stamping and forming process of the sheet metal material, calculate and output the material thickness distribution, residual stress and plastic strain of each sheet metal part after stamping, save the output result in the .dyn file format, and save the material thickness distribution of each sheet metal part in the .dyn file format. , residual stress and plastic strain are imported into the ANSA finite element simulation software to complete the mapping of the stamping simulation results to the stress calculation model, and then the strength simulation of the rear trailer hook is carried out under a single push-pull cycle condition to obtain the stress data of each part under the single push-pull cycle strength simulation considering the influence of stamping, and the stress data of each part under the single push-pull cycle strength simulation is imported into the FEMFAT fatigue simulation calculation software to calculate and output the durability damage and fatigue life of the parts. Furthermore, the results of the fatigue simulation can be judged as qualified in combination with the goal of fatigue simulation. By adding the stamping simulation data of the rear trailer hook and all or part of the sheet metal parts in the white body on which it is installed to the fatigue simulation analysis of the finite element model, the accuracy of the fatigue simulation of the rear trailer hook and its body mounting point can be improved, and the fatigue problems of the actual vehicle in the later stage can be fully exposed in the simulation stage.

[0057] Furthermore, in one embodiment, step S10 includes:

[0058] Based on the design 3D data of the rear trailer hook and the body-in-white, the rear trailer hook and the body-in-white are meshed, connections are established for each part, constraints are set for each connected part, and a finite element simulation model of the rear trailer hook is obtained.

[0059] In this embodiment, the design 3D data of the body-in-white and the rear tow hook crossbeam assembly are imported into the finite element analysis pre-processing software Hypermesh, the sheet metal parts are meshed using 2D units, the tow hook body is meshed using 3D units, the attributes and material information are set according to the actual vehicle status, and connections are established for each part, wherein the rear trailer hook crossbeam assembly is screwed to the body-in-white mounting point according to the assembly form, wherein the welding point is simulated using the ACM method, the glue is simulated using the adhesive method, the welds and bolts are simulated using rigid units, constraints are set for each connected part, the front half of the body-in-white is cut off, and only the rear half of the body of interest is retained, 123456 degrees of freedom are constrained at the cutoff point, and a finite element simulation model of the rear trailer hook is obtained.

[0060] Furthermore, in one embodiment, before step S20, the following steps are included:

[0061] In the finite element simulation model, the initial strength of the rear trailer hook is simulated under a single push-pull cycle to obtain the initial stress data of each part;

[0062] Based on the initial stress data of each part, a first preset number of sheet metal parts having stresses in descending order are selected from each part to obtain a first sheet metal part;

[0063] Selecting a second preset number of sheet metal parts with decreasing feature sharpness from the first sheet metal part to obtain a second sheet metal part;

[0064] The second sheet metal part is determined as a partial part for stamping simulation.

[0065] In this embodiment, in order to improve efficiency, in step S20, stamping simulation can be selected for some sheet metal parts. Specifically, in the finite element simulation software ANSA, the initial strength simulation of a single push-pull cycle working condition is first performed on the rear trailer hook to obtain the initial stress data of each part, and the sheet metal parts with large stress and large feature sharpness are taken as the focus of attention. For example, first, 10 sheet metal parts with stress from large to small are selected from various sheet metal parts as the first sheet metal parts, and then 5 sheet metal parts with feature sharpness from large to small are selected from the 10 first sheet metal parts as the second sheet metal parts, and these 5 sheet metal parts are used as partial parts for stamping simulation.

[0066] Further, in one embodiment, the step of replacing the initial data of corresponding parts with the stamping simulation data of the plurality of sheet metal parts comprises:

[0067] The material thickness simulation distribution, residual stress and plastic strain in the stamping simulation data of multiple sheet metal parts are used to replace the initial distribution of material thickness, initial stress and initial strain in the initial data of the corresponding parts.

[0068] In this embodiment, since the material thickness distribution of sheet metal parts will change after actual stamping, and residual stress and plastic strain will exist, and the material thickness distribution, residual stress and plastic strain will have a great influence on the fatigue simulation analysis results of the rear trailer hook, resulting in the current finite element simulation model being not accurate enough for the fatigue simulation of the rear trailer hook. Therefore, the material thickness distribution, residual stress and plastic strain of each sheet metal part after stamping in the .dyn file format are imported into the ANSA finite element simulation software, and the material thickness simulation distribution, residual stress and plastic strain in the stamping simulation data of multiple sheet metal parts are used to replace the initial material thickness distribution, initial stress and initial strain in the initial data of the corresponding parts, thereby adding the stamping effect of the sheet metal parts to the fatigue simulation analysis of the rear trailer hook, thereby improving the accuracy of the fatigue simulation of the rear trailer hook and its body mounting point, and enabling the fatigue problems of the later actual vehicle to be fully exposed in the simulation stage.

[0069] Further, in one embodiment, referring to Figure 3 , Figure 3 For this application Figure 1 The detailed flow chart of step S40 is as follows: Figure 3 As shown, step S40 includes:

[0070] Step S401, for each sheet metal part to be subjected to stamping simulation, the residual stress in the stamping simulation data is used as the initial stress of the sheet metal part;

[0071] Step S402, for each part, the average stress and stress amplitude of the part are calculated according to the maximum stress and minimum stress under the strength simulation of a single push-pull cycle working condition;

[0072] Step S403, using the average stress of the part and the Morlot equation to correct the material stress-life curve equation of the part to obtain a corrected stress-life curve equation;

[0073] Step S404, substituting the stress amplitude of the part into the corrected stress-life curve equation to calculate the fatigue life of the part;

[0074] Step S405, calculating the durability damage of the part according to the fatigue life of the part.

[0075] In this embodiment, the stress data of each part under the single push-pull cycle strength simulation is imported into the FEMFAT fatigue simulation calculation software, wherein the single push-pull cycle strength simulation includes four load steps, namely, applying a preset tensile force of a first preset angle to the ball head of the rear trailer hook and then unloading, applying a preset thrust force of a second preset angle to the ball head of the rear trailer hook and then unloading, and the TransMAX module in the FEMFAT software is used to construct the stress cycle history of the part. As mentioned above, the material thickness distribution, residual stress and plastic strain will have a great influence on the fatigue simulation analysis results of the rear trailer hook. Therefore, when constructing the stress history curve in the FEMFAT software, it is necessary to select the result of the 0th increment step of the first load step in the stress calculation result, that is, the initial forming stress, as the first data point of the stress time history, and the pulling and pushing conditions are used as subsequent data points. Specifically, in the TimeSteps of the Transmax module of the FEMFAT software, load steps 1-4 in the stress calculation are selected to form a cycle, wherein All every increments is selected in the Stress Load Case Definition, and include increment 0 is checked. Figure 4 , Figure 4 This is a schematic diagram of a stress history curve of an embodiment of a fatigue simulation method for a trailer hook in this application, such as Figure 4 As shown in the figure, since the initial stress generated in the part after forming is taken into account, the stress history curve no longer starts from 0 stress, but from the initial stress, which will affect the average stress, stress amplitude and fatigue simulation results of the part. For each part, the average stress S of the part is calculated based on the maximum stress and minimum stress under the strength simulation of a single push-pull cycle. m and stress amplitude S a , where the stress amplitude S a It is defined by the following formula: Mean stress S m It is defined by the following formula: The stress values ​​of parts in push-pull conditions can be positive or negative. max The absolute value of the maximum stress under the strength simulation of a single push-pull cycle can be taken, S min The absolute value of the minimum stress under the strength simulation of a single push-pull cycle can be taken. Furthermore, the material stress-life curve of the part, namely the SN curve, can be obtained by experiment and can usually be defined by the following formula: S a =S′ f (2N f ) b , where S a is the stress amplitude, N f is the fatigue life of the part, that is, the number of cycles the part goes through until fatigue failure, S′ fand b are the key parameters for defining the SN curve, where S′ f is the fatigue strength coefficient, b is the fatigue strength index, both of which can be obtained from the fatigue test of the material. The above SN curve is the reference curve of the material, which is usually obtained from the fatigue test under symmetrical cyclic load, and the average stress in the actual use condition of the part is not considered. In the high-cycle fatigue area, the average normal stress has a significant effect on the fatigue properties of the part, directly affecting the opening or closing state of the microcracks. In order to compensate for the influence of the average tensile stress on the high-cycle fatigue properties, the Morlot equation is used to correct the average stress of the reference SN curve. The corrected SN curve equation is as follows: S a =(S′ f -S m )(2N f ) b , substitute the stress amplitude of the part into the modified stress-life curve equation to calculate the fatigue life N of the part under given working conditions. f , we can further calculate the durability damage of the parts after N cycles: At this point, the fatigue simulation calculation of the rear trailer hook is completed, and the results of the fatigue simulation can be judged whether they are qualified in combination with the goal of the fatigue simulation.

[0076] Furthermore, in one embodiment, the strength simulation of a single push-pull cycle of the rear trailer hook includes:

[0077] The vehicle is unloaded after applying a preset pulling force of a first preset angle to the ball head of the rear trailer hook, and the vehicle is unloaded after applying a preset thrust of a second preset angle to the ball head of the rear trailer hook.

[0078] In this embodiment, you can continue to refer to Figure 2 ,like Figure 2 As shown, a symmetrical cyclic load with an oblique angle of 20° is applied to the ball head of the rear trailer hook. The symmetrical cyclic load includes four load steps. Specifically, load step 1 is established to apply a pulling force of 5140N at the ball head position along an oblique upward angle of 20°, load step 2 is established to unload, load step 3 is established to apply a thrust of 5140N at the ball head position along an oblique downward angle of 20°, and load step 4 is established to unload. By performing strength simulation of a single push-pull cycle working condition on the rear trailer hook, the stress data of each part under the single push-pull cycle working condition strength simulation is obtained for subsequent fatigue simulation analysis.

[0079] In a second aspect, an embodiment of the present application also provides a rear trailer hook fatigue simulation device.

[0080] In one embodiment, referring to Figure 5 , Figure 5 This is a functional module diagram of an embodiment of the rear trailer hook fatigue simulation device of the present application, as shown in FIG. Figure 5 As shown, the rear trailer hook fatigue simulation device includes:

[0081] The model building module 10 is used to build a finite element simulation model of the rear trailer hook based on the design three-dimensional data of the rear trailer hook and the body-in-white, wherein the rear trailer hook is installed on the body-in-white, and the rear trailer hook and the body-in-white both include multiple parts, and the multiple parts include sheet metal parts;

[0082] A stamping simulation module 20 is used to perform stamping simulation on all or part of the sheet metal parts to obtain stamping simulation data of multiple sheet metal parts;

[0083] The strength simulation module 30 is used to replace the initial data of the corresponding parts with the stamping simulation data of multiple sheet metal parts in the finite element simulation model, perform the strength simulation of a single push-pull cycle working condition on the rear trailer hook, and obtain the stress data of each part;

[0084] The fatigue simulation module 40 is used to perform fatigue simulation on the rear trailer hook based on the stress data of each component to obtain the durable damage and fatigue life of each component.

[0085] Furthermore, in one embodiment, the model building module 10 is used to:

[0086] Based on the design 3D data of the rear trailer hook and the body-in-white, the rear trailer hook and the body-in-white are meshed, connections are established for each part, constraints are set for each connected part, and a finite element simulation model of the rear trailer hook is obtained.

[0087] Furthermore, in one embodiment, the rear trailer hook fatigue simulation device further includes a stamping part determination module, which is used to:

[0088] In the finite element simulation model, the initial strength of the rear trailer hook is simulated under a single push-pull cycle to obtain the initial stress data of each part;

[0089] Based on the initial stress data of each part, a first preset number of sheet metal parts having stresses in descending order are selected from each part to obtain a first sheet metal part;

[0090] Selecting a second preset number of sheet metal parts with decreasing feature sharpness from the first sheet metal part to obtain a second sheet metal part;

[0091] The second sheet metal part is determined as a partial part for stamping simulation.

[0092] Furthermore, in one embodiment, the strength simulation module 30 is further used to:

[0093] The material thickness simulation distribution, residual stress and plastic strain in the stamping simulation data of multiple sheet metal parts are used to replace the initial distribution of material thickness, initial stress and initial strain in the initial data of the corresponding parts.

[0094] Furthermore, in one embodiment, the fatigue simulation module 40 is also used for:

[0095] For each sheet metal part subjected to stamping simulation, the residual stress in the stamping simulation data is used as the initial stress of the sheet metal part;

[0096] For each part, the average stress and stress amplitude of the part are calculated based on the maximum stress and minimum stress under the strength simulation of a single push-pull cycle;

[0097] Using the average stress of the part, the Morlot equation is used to correct the material stress-life curve equation of the part to obtain the corrected stress-life curve equation;

[0098] Substitute the stress amplitude of the part into the modified stress-life curve equation to calculate the fatigue life of the part;

[0099] Based on the fatigue life of the parts, the durable damage of the parts is calculated.

[0100] Furthermore, in one embodiment, the strength simulation module 30 is further used to:

[0101] The vehicle is unloaded after applying a preset pulling force of a first preset angle to the ball head of the rear trailer hook, and the vehicle is unloaded after applying a preset thrust of a second preset angle to the ball head of the rear trailer hook.

[0102] Among them, the functional implementation of each module in the above-mentioned rear trailer hook fatigue simulation device corresponds to the various steps in the above-mentioned rear trailer hook fatigue simulation method embodiment, and its functions and implementation processes will not be repeated here one by one.

[0103] In a third aspect, an embodiment of the present application provides a rear trailer hook fatigue simulation device.

[0104] Reference Figure 6 , Figure 6 Schematic diagram of the hardware structure of the rear trailer hook fatigue simulation device involved in the embodiment of the present application. In the embodiment of the present application, the rear trailer hook fatigue simulation device may include a processor, a memory, a communication interface and a communication bus.

[0105] The communication bus may be of any type and is used to interconnect the processor, the memory, and the communication interface.

[0106] The communication interface includes input / output (I / O) interface, physical interface and logical interface, etc., which are used to realize the interconnection of devices inside the rear trailer hook fatigue simulation device, and the interface used to realize the interconnection of the rear trailer hook fatigue simulation device with other devices (such as other computing devices or user devices). The physical interface can be an Ethernet interface, an optical fiber interface, an ATM interface, etc.; the user device can be a display, a keyboard, etc.

[0107] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0108] The processor may be a general-purpose processor, and the general-purpose processor may call the rear trailer hook fatigue simulation program stored in the memory and execute the rear trailer hook fatigue simulation method provided in the embodiment of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the rear trailer hook fatigue simulation program is called may refer to the various embodiments of the rear trailer hook fatigue simulation method of the present application, and will not be described in detail here.

[0109] Those skilled in the art will understand that Figure 6 The hardware structure shown in the figure does not constitute a limitation on the present application, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0110] In a fourth aspect, an embodiment of the present application also provides a readable storage medium.

[0111] A rear trailer hook fatigue simulation program is stored on the readable storage medium of the present application, wherein when the rear trailer hook fatigue simulation program is executed by the processor, the steps of the rear trailer hook fatigue simulation method as described above are implemented.

[0112] Among them, the method implemented when the rear trailer hook fatigue simulation program is executed can refer to the various embodiments of the rear trailer hook fatigue simulation method of the present application, and will not be repeated here.

[0113] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0114] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit "first", "second" and "third" to different types.

[0115] In the description of the embodiments of the present application, "exemplary", "for example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary", "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "for example" or "for example" is intended to present related concepts in a specific way.

[0116] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or. For example, A / B can mean A or B. The “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0117] In some processes described in the embodiments of the present application, multiple operations or steps that appear in a specific order are included, but it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or in parallel, and the sequence number of the operation is only used to distinguish the different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in sequence or in parallel, and these operations or steps may be combined.

[0118] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, disk, CD) as described above, and includes a number of instructions for a terminal device to execute the methods described in each embodiment of the present application.

[0119] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A rear trailer hook fatigue simulation method, characterized in that: The rear trailer hook fatigue simulation method comprises: Based on the design three-dimensional data of the rear trailer hook and the body-in-white, a finite element simulation model of the rear trailer hook is established, wherein the rear trailer hook is installed on the body-in-white, and both the rear trailer hook and the body-in-white include multiple parts, and the multiple parts include sheet metal parts; Perform stamping simulation on all or part of the sheet metal parts to obtain stamping simulation data of multiple sheet metal parts; In the finite element simulation model, the stamping simulation data of multiple sheet metal parts are used to replace the initial data of the corresponding parts, and the strength simulation of a single push-pull cycle working condition of the rear trailer hook is performed to obtain the stress data of each part; Based on the stress data of each part, fatigue simulation of the rear trailer hook is carried out to obtain the durable damage and fatigue life of each part.

2. The rear trailer hook fatigue simulation method according to claim 1, characterized in that: The finite element simulation model of the rear trailer hook is established based on the three-dimensional design data of the rear trailer hook and the body in white, including: Based on the design 3D data of the rear trailer hook and the body-in-white, the rear trailer hook and the body-in-white are meshed, connections are established for each part, constraints are set for each connected part, and a finite element simulation model of the rear trailer hook is obtained.

3. The rear trailer hook fatigue simulation method according to claim 1, characterized in that: Before performing stamping simulation on all or part of the sheet metal parts to obtain stamping simulation data of multiple sheet metal parts, the method includes: In the finite element simulation model, the initial strength of the rear trailer hook is simulated under a single push-pull cycle to obtain the initial stress data of each part; Based on the initial stress data of each part, a first preset number of sheet metal parts having stresses in descending order are selected from each part to obtain a first sheet metal part; Selecting a second preset number of sheet metal parts with decreasing feature sharpness from the first sheet metal part to obtain a second sheet metal part; The second sheet metal part is determined as a partial part for stamping simulation.

4. The rear trailer hook fatigue simulation method according to claim 1, characterized in that: The method of using the stamping forming simulation data of the plurality of sheet metal parts to replace the initial data of the corresponding parts includes: The material thickness simulation distribution, residual stress and plastic strain in the stamping simulation data of multiple sheet metal parts are used to replace the initial distribution of material thickness, initial stress and initial strain in the initial data of the corresponding parts.

5. The rear trailer hook fatigue simulation method according to claim 1, characterized in that: Based on the stress data of each part, fatigue simulation is performed on the rear trailer hook to obtain the durable damage and fatigue life of each part, including: For each sheet metal part subjected to stamping simulation, the residual stress in the stamping simulation data is used as the initial stress of the sheet metal part; For each part, the average stress and stress amplitude of the part are calculated based on the maximum stress and minimum stress under the strength simulation of a single push-pull cycle; Using the average stress of the part, the Morlot equation is used to correct the material stress-life curve equation of the part to obtain the corrected stress-life curve equation; Substitute the stress amplitude of the part into the modified stress-life curve equation to calculate the fatigue life of the part; Based on the fatigue life of the parts, the durable damage of the parts is calculated.

6. The rear trailer hook fatigue simulation method according to claim 1, characterized in that: The strength simulation of a single push-pull cycle working condition of the rear trailer hook includes: The vehicle is unloaded after applying a preset pulling force of a first preset angle to the ball head of the rear trailer hook, and the vehicle is unloaded after applying a preset thrust of a second preset angle to the ball head of the rear trailer hook.

7. A rear trailer hook fatigue simulation device, characterized in that: The rear trailer hook fatigue simulation device comprises: A model building module is used to build a finite element simulation model of the rear trailer hook based on the design three-dimensional data of the rear trailer hook and the body-in-white, wherein the rear trailer hook is installed on the body-in-white, and the rear trailer hook and the body-in-white both include multiple parts, and the multiple parts include sheet metal parts; A stamping simulation module is used to perform stamping simulation on all or part of the sheet metal parts to obtain stamping simulation data of multiple sheet metal parts; Strength simulation module, used to replace the initial data of corresponding parts with the stamping simulation data of multiple sheet metal parts in the finite element simulation model, perform strength simulation of a single push-pull cycle on the rear trailer hook, and obtain stress data of each part; The fatigue simulation module is used to perform fatigue simulation on the rear trailer hook based on the stress data of each part to obtain the durable damage and fatigue life of each part.

8. The rear trailer hook fatigue simulation device according to claim 7, characterized in that: The model building module is used to: Based on the design 3D data of the rear trailer hook and the body-in-white, the rear trailer hook and the body-in-white are meshed, connections are established for each part, constraints are set for each connected part, and a finite element simulation model of the rear trailer hook is obtained.

9. A rear trailer hook fatigue simulation device, characterized in that: The rear trailer hook fatigue simulation device includes a processor, a memory, and a rear trailer hook fatigue simulation program stored in the memory and executable by the processor, wherein when the rear trailer hook fatigue simulation program is executed by the processor, the steps of the rear trailer hook fatigue simulation method as described in any one of claims 1 to 6 are implemented.

10. A readable storage medium, characterized in that: The readable storage medium stores a rear trailer hook fatigue simulation program, wherein when the rear trailer hook fatigue simulation program is executed by the processor, the steps of the rear trailer hook fatigue simulation method according to any one of claims 1 to 6 are implemented.

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