Method for calculating welding residual stress and deformation of control arm of automotive suspension component

Abstract

The invention relates to a method for calculating welding residual stress and deformation of a control arm of an automobile suspension component, which comprises the following steps of: acquiring a three-dimensional model of the control arm of the automobile suspension component, performing grid division processing on the three-dimensional model, and storing the three-dimensional model after grid division into a format capable of being identified by welding simulation software; all parts of the control arm are imported into welding simulation software, a welding heat source model is selected in the welding simulation software, simulation parameters are set, a welding seam of the control arm is selected in the welding simulation software for thermal elastic-plastic simulation, a simulation result is obtained, and the simulation result is compared with an experimental result to check the heat source model; and extracting a thermal cycle curve of the center of the welding seam from a welding temperature field obtained from the checked heat source model, loading the thermal cycle curve on each welding seam in the control arm, and performing simulation calculation in welding simulation software to obtain a calculation result. According to the method, the calculation speed is increased, and the problems of difficult model establishment of the welding structure and long finite element calculation time are solved.

Description

Technical Field

[0001] The invention relates to the technical field of welding of a control arm of an automobile suspension component, and in particular to a method for calculating welding residual stress and deformation of a control arm of an automobile suspension component. Background Art

[0002] As the guiding and force transmission element of the automobile suspension system, the control arm of the automobile suspension component transmits various forces acting on the wheel to the body, and at the same time ensures that the wheel can move according to the prescribed trajectory. In recent years, in the development of automobile lightweight and comfort, the structure of the control arm of the automobile suspension component has played an important role, and has a great impact on the vehicle's handling stability, driving safety and smoothness. The use of welding methods to manufacture control arms can greatly reduce the weight of the control arm and improve the production efficiency of the control arm. However, due to the uneven distribution of arc temperature at the welding structure position, a large temperature gradient is formed between the weld and the base material, and a large residual stress will be generated during the subsequent cooling process. The residual stress and the service load will accelerate the fatigue failure at the joint position, seriously affecting the reliability of the suspension component control arm structure.

[0003] In order to reduce the residual stress level at the welding structure of the suspension control arm, it is necessary to optimize the welding process and welding fixture of the suspension control arm. Most of the current methods are to formulate welding processes and select fixtures based on the experience of welding technicians, and the residual stress and deformation of the joint position after welding are large. In recent years, with the development of welding numerical simulation technology, the use of welding simulation technology to study and control the stress and deformation of welded structures is an effective method. However, there are two problems for large and complex welded structures. First, the finite element model used for simulation calculation is difficult to obtain, especially for structures similar to control arms. The upper and lower pieces are stamping parts, and the detailed dimensions in the physical object are unknown. It is difficult to establish a physical model of the control arm through three-dimensional modeling software; second, the conventional thermoelastic-plastic calculation method is not only labor-intensive but also time-consuming when calculating large and complex welded structures. Although the inherent strain method can save calculation time, the accuracy of the results will be greatly reduced. For this reason, further improvements to the existing technology are needed. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for calculating the welding residual stress and deformation of the control arm of an automobile suspension component, which can save calculation time and has high calculation accuracy, in view of the above-mentioned prior art.

[0005] The technical solution adopted by the present invention to solve the above technical problem is: a method for calculating the welding residual stress and deformation of the control arm of an automobile suspension component, characterized by comprising the following steps: Step 1: Scan the control arm of the automobile suspension component to obtain a three-dimensional model of the control arm of the automobile suspension component; Step 2: Mesh the three-dimensional model of the control arm of the automobile suspension component, and save the meshed three-dimensional model into a format that can be recognized by welding simulation software; Step 3, importing the components of the automobile suspension component control arm in a format that can be recognized by the welding simulation software in step 2 into the welding simulation software, selecting a welding heat source model and setting simulation parameters in the welding simulation software, and selecting a weld of the automobile suspension component control arm in the welding simulation software for thermoelastic-plastic simulation to obtain a simulation result; Step 4: Perform a thermoelastic-plastic test on the weld of the control arm of the automobile suspension component selected in step 3, obtain the experimental results, and compare the experimental results with the simulation results to calibrate the heat source model in step 3, until the difference between the simulation results and the experimental results is less than or equal to β, where β is a constant close to 0, that is, a calibrated heat source model is obtained; Step 5: Extract the thermal cycle curve of the weld center from the welding temperature field obtained from the calibrated heat source model, load the thermal cycle curve on each weld in the control arm of the automobile suspension component, perform simulation calculations in the welding simulation software, and obtain the welding temperature field, residual stress field and deformation field results corresponding to the control arm of the automobile suspension component.

[0006] In order to improve the calculation efficiency, when the three-dimensional model of the automobile suspension component control arm is meshed in step 2, the mesh of the weld position in the three-dimensional model of the automobile suspension component control arm is encrypted, and the meshes are all hexahedrons.

[0007] Preferably, in step 2, Hypermesh software is used to perform meshing processing on the three-dimensional model of the control arm of the automobile suspension component.

[0008] In order to reduce the amount of calculation, before the three-dimensional model after meshing is saved in step 2 as a format file that can be recognized by the welding simulation software, the following steps are also included: In the Hypermesh software, the solid part of the three-dimensional model after meshing is deleted, and only the content of the mesh part is retained. Then the mesh model of each component of the control arm of the automobile suspension component is saved in a format that can be recognized by the welding simulation software.

[0009] Preferably, the welding simulation software in step 3 is Simufact.welding software.

[0010] Preferably, the simulation parameters in step 3 include material parameters, heat source parameters, and heat dissipation and cooling conditions.

[0011] Preferably, before performing simulation calculation in welding simulation software in step 5, the following steps are also included: Set the welding sequence of each weld in the control arm of the automobile suspension component.

[0012] Compared with the prior art, the advantages of the present invention are: by obtaining a three-dimensional model of the control arm of an automobile suspension component and meshing it, the welding process is simulated using welding simulation software, and in addition, on the basis of a calibrated heat source model, the thermal cycle curve of the center of the weld is extracted, so that the thermal cycle curve of the center of the weld is used to perform heating and cooling calculations on the entire weld, thereby accelerating the calculation speed and greatly reducing the calculation time of the welding process of the control arm of the suspension component, solving the problems of difficulty in model establishment and time-consuming finite element calculation of the welding structure of the automobile control arm, and providing a solution and method for the calculation of welding residual stress and deformation of large and complex welded structural parts such as automobile control arms, and the method is simple to operate, low in cost, high in efficiency, high in accuracy, and easy to promote and apply. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A flow chart of a method for calculating welding residual stress and deformation of a control arm of an automobile suspension component in an embodiment of the present invention; Figure 2 A physical picture of a control arm of a vehicle suspension component to be calculated in an embodiment of the present invention; Figure 3 To obtain Figure 2 3D model diagram of the control arm of the automobile suspension component; Figure 4 For Figure 3 The three-dimensional model after meshing; Figure 5 This is a schematic diagram of the components of the automobile suspension control arm saved using Hypermesh software, where Figure 5 (a) is the outer liner, Figure 5 (b) is the upper fixed frame. Figure 5 (c) in the figure is the lower fixing frame. Figure 5 (d) in the figure is the weld on the liner. Figure 5 (e) in the figure is the weld on the fixed frame. Figure 5 (f) in the figure is the weld under the liner. Figure 5 (g) in the figure is the weld under the fixed frame. Figure 5 (h) in the figure is the middle weld of the fixing frame; Figure 6 This is the temperature field distribution diagram at a certain moment simulated in Simufact.welding software; Figure 7 It is a thermal cycle curve diagram extracted from the weld center of the calibrated welding temperature field; Figure 8 This is a schematic diagram of the temperature field calculated using the thermal cycle curve in the Simufact.welding software; Fig. 9 Schematic diagram of residual stress field calculated using thermal cycle curve in Simufact.welding software; Fig.10 Schematic diagram of the deformation field calculated using the thermal cycle curve in Simufact.welding software. DETAILED DESCRIPTION

[0014] The present invention is further described in detail below with reference to the accompanying drawings.

[0015] like Figure 1 As shown, the method for calculating the welding residual stress and deformation of the control arm of the automobile suspension component in this embodiment includes the following steps: Step 1: Scan the control arm of the automobile suspension component to obtain a three-dimensional model of the control arm of the automobile suspension component; In this embodiment, the control arm of the automobile suspension component is scanned by a three-dimensional scanner, the accuracy of the three-dimensional scanner is ≥ 0.01 mm, the resolution is ≥ 0.01 mm, and the three-dimensional model of the control arm of the automobile suspension component is in the stp format; Step 2: Mesh the three-dimensional model of the control arm of the automobile suspension component, and save the meshed three-dimensional model into a format that can be recognized by welding simulation software; In this embodiment, the three-dimensional model of the automobile suspension component control arm is meshed using Hypermesh software; in addition, when the three-dimensional model of the automobile suspension component control arm is meshed, the mesh of the weld position in the three-dimensional model of the automobile suspension component control arm is encrypted, and the meshes are all hexahedrons; the mesh size at the weld is 1 mm or 2 mm, and the mesh size at the base material is 6 mm or 8 mm; Before the meshed three-dimensional model is saved in a format that can be recognized by welding simulation software, the following steps are also included: in Hypermesh software, the entity part of the meshed three-dimensional model is deleted, and only the content of the mesh part is retained, and then the mesh model of each component of the automobile suspension component control arm is saved in a format that can be recognized by welding simulation software. In this embodiment, the format that can be recognized by welding simulation software is bdf format; Step 3, importing the components of the automobile suspension component control arm in a format that can be recognized by the welding simulation software in step 2 into the welding simulation software, selecting a welding heat source model and setting simulation parameters in the welding simulation software, and selecting a weld of the automobile suspension component control arm in the welding simulation software for thermoelastic-plastic simulation to obtain a simulation result; In this embodiment, the welding simulation software is Simufact.welding software, which can recognize files in bdf format; the above simulation parameters include material parameters, heat source parameters, and heat dissipation and cooling conditions; Step 4: Perform a thermoelastic-plastic test on the weld of the control arm of the automobile suspension component selected in step 3, obtain the experimental results, and compare the experimental results with the simulation results to calibrate the heat source model in step 3, until the difference between the simulation results and the experimental results is less than or equal to β, where β is a constant close to 0, that is, a calibrated heat source model is obtained; The simulation results and experimental results in this embodiment both refer to the heat-affected contour size of the weld cross section, that is, the heat source model in step 3 is verified by comparing the experimental results of the heat-affected contour size of the weld cross section with the simulation results; in addition, in this embodiment, verifying the heat source model refers to verifying the boundary condition settings, the heat source itself, etc.; Step 5: Extract the thermal cycle curve of the weld center from the welding temperature field obtained from the calibrated heat source model, load the thermal cycle curve on each weld in the control arm of the automobile suspension component, perform simulation calculations in the welding simulation software, and obtain the welding temperature field, residual stress field and deformation field results corresponding to the control arm of the automobile suspension component.

[0016] Before performing simulation calculation in the welding simulation software, the present embodiment also includes the following steps: setting the welding sequence of each weld in the control arm of the automobile suspension component.

[0017] The following is a further explanation of the method of the present invention by taking the calculation of welding residual stress and deformation of a control arm structure of a new energy vehicle suspension component as an example. Figure 2 As shown, the specific calculation process is: The control arm is scanned with a 3D scanner to obtain a 3D model of the control arm. Figure 3 As shown; the three-dimensional model of the control arm is meshed using Hypermesh software, and the results are as follows Figure 4 As shown; save the meshed model into bdf format; Import the control arm components in bdf format into Simufact.welding software one by one, and the results are as follows: Figure 5 As shown in the figure, the calculation model of the control arm is then combined; according to the specified welding process parameters, the material parameters, heat source parameters, clamping conditions, heat dissipation and cooling conditions of the control arm are set in the Simufact.welding software, and a weld of the control arm is selected for thermal elastic-plastic simulation. The temperature field distribution at a certain moment of the simulation is shown in Figure 6 As shown; The simulation results are compared with the experimental results obtained from the thermoelastic-plastic test of the weld of the selected automobile suspension control arm to calibrate the heat source model and obtain the welding temperature field from the calibrated heat source model; Extract the thermal cycle curve from the weld center of the calibrated welding temperature field as follows Figure 7 As shown, the thermal cycle curve is loaded on each weld of the control arm; according to the current welding sequence or the designed welding sequence, in the Simufact.welding software, select Thermomechanicalsolution under the General analysis settings menu, and then submit the calculation. After the calculation is completed, check the control arm welding temperature field in the results as shown in the figure. Figure 8 As shown, the residual stress field of the control arm welding is as follows Fig. 9 As shown, the control arm welding deformation field is as follows Fig.10 shown.

[0018] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for calculating the residual stress and deformation of the control arm welding of an automobile suspension component, characterized in that The steps include: Step 1: Scan the control arm of the automobile suspension component to obtain a three-dimensional model of the control arm of the automobile suspension component; Step 2: Mesh the three-dimensional model of the control arm of the automobile suspension component, and save the meshed three-dimensional model into a format that can be recognized by welding simulation software; Step 3, importing the components of the automobile suspension component control arm in a format that can be recognized by the welding simulation software in step 2 into the welding simulation software, selecting a welding heat source model and setting simulation parameters in the welding simulation software, and selecting a weld of the automobile suspension component control arm in the welding simulation software for thermoelastic-plastic simulation to obtain a simulation result; Step 4: Perform a thermoelastic-plastic test on the weld of the control arm of the automobile suspension component selected in step 3, obtain the experimental results, and compare the experimental results with the simulation results to calibrate the heat source model in step 3, until the difference between the simulation results and the experimental results is less than or equal to β, where β is a constant close to 0, that is, a calibrated heat source model is obtained; Step 5: Extract the thermal cycle curve of the weld center from the welding temperature field obtained from the calibrated heat source model, load the thermal cycle curve on each weld in the control arm of the automobile suspension component, perform simulation calculations in the welding simulation software, and obtain the welding temperature field, residual stress field and deformation field results corresponding to the control arm of the automobile suspension component.

2. The method according to claim 1, characterized in that: When the three-dimensional model of the automobile suspension component control arm is meshed in step 2, the mesh of the weld position in the three-dimensional model of the automobile suspension component control arm is controlled to be encrypted, and the meshes are all hexahedrons.

3. The method according to claim 2, characterized in that: In the step 2, Hypermesh software is used to perform meshing processing on the three-dimensional model of the control arm of the automobile suspension component.

4. The method according to claim 3, characterized in that: Before the three-dimensional model after meshing is saved in the format that can be recognized by the welding simulation software in step 2, the following steps are also included: In the Hypermesh software, the solid part of the three-dimensional model after meshing is deleted, and only the content of the mesh part is retained. Then the mesh model of each component of the control arm of the automobile suspension component is saved in a format that can be recognized by the welding simulation software.

5. The method according to any one of claims 1 to 4, characterized in that: The welding simulation software in step 3 is Simufact.welding software.

6. The method according to claim 5, characterized in that: The simulation parameters in step 3 include material parameters, heat source parameters, and heat dissipation and cooling conditions.

7. The method according to claim 5, characterized in that: Before performing simulation calculation in the welding simulation software in step 5, the following steps are also included: Set the welding sequence of each weld in the control arm of the automobile suspension component.

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