A welding simulation method, apparatus, equipment, storage medium, and program product.

Abstract

This invention discloses a welding simulation method, apparatus, device, storage medium, and program product. The method involves dividing the welding model into a first grid and a second grid, with the first and second grids having different sizes. Multiple grid cells on the second grid closest to the moving heat source at the current moment are obtained as a local computational region. Boundary conditions with fixed temperature and displacement are set in the local computational region to calculate the local temperature field and local stress-deformation field. The local temperature field and local stress of the local computational region are mapped onto the corresponding first grid, and the global temperature field and overall stress of the welding model are calculated. Based on the global temperature field and overall stress of the welding model at various moments during the welding process, the welding deformation of the welding model is obtained. Using this invention, the computational load and simulation time in the welding simulation process can be effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of data simulation technology, and in particular to a welding simulation method, apparatus, equipment, storage medium, and program product. Background Technology

[0002] To understand the heating and deformation of a structure during welding, the finite element method is typically used to calculate transient heat conduction and stress-strain.

[0003] Currently, existing welding process simulation technologies suffer from two main drawbacks: First, existing methods employ a global finite element mesh to sequentially calculate the welding temperature field and thermal deformation. Solving this global mesh results in a significant computational load, substantially increasing the computational burden and simulation time, and consuming substantial memory resources. This is particularly problematic when dealing with large, complex structures, severely limiting the ability to solve problems quickly. Second, existing methods typically require heat conduction analysis before stress-strain analysis. This sequential process increases simulation time, and when analyzing multiple welding conditions, the simulation requires considerable waiting time, further reducing simulation efficiency. Therefore, existing methods struggle to address the issues of time-consuming and computationally intensive simulations of large-size, long-weld structures. Summary of the Invention

[0004] The purpose of this invention is to provide a welding simulation method, apparatus, equipment, storage medium, and program product that can effectively reduce the amount of computation and simulation time in the welding simulation calculation process.

[0005] To achieve the above objectives, embodiments of the present invention provide a welding simulation method, comprising:

[0006] The welding model is meshed using a first mesh and a second mesh, respectively; wherein the first mesh and the second mesh are of different sizes.

[0007] Obtain multiple grid cells on the second grid that are currently close to the moving heat source as a local computational region;

[0008] Boundary conditions with fixed temperature and displacement are set in the local calculation region to calculate the local temperature field and local stress-deformation field of the local calculation region.

[0009] The local temperature field and local stress of the local calculation region are mapped onto the corresponding first grid, and the global temperature field and overall stress of the welding model are calculated respectively.

[0010] Based on the global temperature field and overall stress of the welding model at various times during the welding process, the welding deformation of the welding model is obtained.

[0011] As an improvement to the above scheme, obtaining multiple grid cells on the second grid that are currently close to the moving heat source as a local computational region includes:

[0012] On the second grid of the welding model, the size of the spheres dividing the fixed and non-fixed regions is determined by a one-dimensional heat transfer model; wherein, the fixed region is the region with a lower temperature or that has been cooled at the current moment, and the non-fixed region is the region that is close to the moving heat source at the current moment;

[0013] The sphere is used to divide each grid cell into fixed and non-fixed regions, and the non-fixed regions are used as local computational regions.

[0014] As an improvement to the above scheme, the determination of the sphere size for dividing the fixed and non-fixed regions on the second grid of the welding model using a one-dimensional heat transfer model includes:

[0015] The critical position is calculated based on the initial temperature of the welding model and the preset Gaussian error function; wherein, the critical position is the position where the initial temperature rises to the transient temperature, and the Gaussian error function is used to describe the error of the temperature distribution;

[0016] The radius of the sphere is calculated based on the critical position and the moving speed of the moving heat source.

[0017] As an improvement to the above scheme, the step of mapping the local temperature field of the local computational region onto the corresponding first grid and calculating the global temperature field of the welding model includes:

[0018] The heat distribution on the first grid is determined based on the characteristics of the moving heat source, and the initial global temperature field of the welding model is calculated based on heat conduction.

[0019] The local temperature field of the local computational region is mapped onto the first grid to cover the corresponding part of the data in the initial global temperature field, thereby updating the global temperature field of the welding model.

[0020] As an improvement to the above scheme, the step of mapping the local temperature field of the local computational region onto the first grid to cover the corresponding part of the data in the initial global temperature field and updating the global temperature field of the welding model includes:

[0021] The normalized coordinates of each node in the first grid corresponding to the second grid are calculated using the Newton-Raphson method.

[0022] Using element shape functions, the temperature value of the node corresponding to the first mesh is calculated by interpolation of the temperature value of the local temperature field in the local computational region. The initial global temperature field is then updated to obtain the global temperature field of the welding model.

[0023] As an improvement to the above scheme, the step of mapping the local stress of the local calculation region onto the corresponding first mesh and calculating the overall stress of the welding model includes:

[0024] The local stress of the local calculation region is mapped to the first mesh for overall stress balance calculation to obtain the overall stress of the welding model.

[0025] This invention also provides a welding simulation device, comprising:

[0026] The mesh generation module is used to divide the welding model into a first mesh and a second mesh, respectively; wherein the first mesh and the second mesh are of different sizes.

[0027] The local computational region acquisition module is used to acquire multiple grid cells on the second grid that are close to the moving heat source at the current moment as local computational regions;

[0028] The local calculation region calculation module is used to set boundary conditions with fixed temperature and displacement in the local calculation region in order to calculate the local temperature field and local stress deformation field of the local calculation region.

[0029] The mesh mapping module is used to map the local temperature field and local stress of the local calculation region onto the corresponding first mesh, and to calculate the global temperature field and overall stress of the welding model respectively.

[0030] The welding deformation acquisition module is used to obtain the welding deformation of the welding model based on the global temperature field and overall stress of the welding model at various times during the welding process.

[0031] This invention also provides a welding simulation device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the welding simulation method as described in any of the above embodiments.

[0032] This invention also provides a computer-readable storage medium, which includes a stored computer program, wherein the computer program, when running, controls the device where the computer-readable storage medium is located to execute the welding simulation method as described in any of the above embodiments.

[0033] This invention also provides a computer program product, which includes a computer program or computer instructions. When the computer program or computer instructions are executed by a processor, they implement the welding simulation method as described in any of the above embodiments.

[0034] Compared with existing technologies, the welding simulation method, apparatus, equipment, storage medium, and program products disclosed in this invention address the problems of large overall computational load and long waiting time during analysis in existing technologies for simulating the heat source movement process. They propose a mesh-local solution-global mapping technique, specifying the region near the heat source as the local computational region on a fine mesh. By dynamically fixing some nodes to reduce degrees of freedom, high-precision solutions for non-fixed regions near the heat source are guaranteed. These solutions are then mapped onto a coarse mesh to obtain the overall temperature and deformation fields, thus forming a thermo-elastic-plastic finite element method with high computational efficiency, low storage space, and large time step, giving the thermoplastic finite element method its advantages. Furthermore, to address the shortcomings of existing technologies that perform sequential calculations of heat conduction analysis followed by stress-strain analysis, a parallel computation method for heat conduction and stress solution modules is proposed, eliminating the waiting time during heat conduction analysis and further improving simulation efficiency. The embodiments of this invention relate to an efficient method for calculating temperature and deformation during welding processes, which can be directly applied to the field of welding process simulation technology for metal structures. Attached Figure Description

[0035] Figure 1 This is a schematic flowchart of a welding simulation method provided in an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram illustrating the principle of the welding simulation method in this embodiment of the invention;

[0037] Figure 3 This is a schematic diagram illustrating the principle of calculating the size of a non-fixed region in an embodiment of the present invention;

[0038] Figure 4 This is a schematic diagram of the heat source location and local calculation area in an embodiment of the present invention;

[0039] Figure 5 This is a schematic diagram illustrating the principle of mesh mapping in an embodiment of the present invention;

[0040] Figure 6 This is a schematic diagram illustrating the principle of solving welding deformation in an embodiment of the present invention;

[0041] Figure 7 This is a schematic diagram of the structure of a welding simulation device provided in an embodiment of the present invention. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0044] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0045] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0046] See Figure 1 This is a flowchart illustrating a welding simulation method provided in an embodiment of the present invention. The embodiment of the present invention provides a welding simulation method, including steps S11 to S14:

[0047] S11. The welding model is meshed using a first mesh and a second mesh, respectively; wherein the first mesh and the second mesh are of different sizes.

[0048] S12. Obtain multiple grid cells on the second grid that are currently close to the moving heat source as a local calculation region;

[0049] S13. Set boundary conditions with fixed temperature and displacement in the local calculation region to calculate the local temperature field and local stress deformation field of the local calculation region.

[0050] S14. Map the local temperature field and local stress of the local calculation region onto the corresponding first grid, and calculate the global temperature field and overall stress of the welding model respectively.

[0051] S15. Based on the global temperature field and overall stress of the welding model at various times during the welding process, the welding deformation of the welding model is obtained.

[0052] In this embodiment of the invention, a three-dimensional or two-dimensional finite element model is first established based on the geometry, material properties, etc. of the welded parts, serving as the welding model. Next, mesh generation is performed. This scheme uses a first mesh and a second mesh to mesh the welding model, with the first mesh and the second mesh having different sizes.

[0053] Optionally, the size of the first grid is larger than the size of the second grid, that is, the first grid is a coarse grid and the second grid is a fine grid. The fine grid is used for local high-precision calculations, and the coarse grid is used for overall structural analysis.

[0054] Next, material parameters are set. By inputting the thermophysical properties of the welding material, such as thermal conductivity, specific heat capacity, and melting point, the mechanical properties of the material, such as elastic modulus, yield strength, and hardening coefficient, are set for subsequent stress-deformation analysis.

[0055] See Figure 2 This is a schematic diagram illustrating the principle of the welding simulation method in this embodiment of the invention. This embodiment designs a rapid welding simulation method based on local and global mesh mapping. On a fine mesh, there is no need to solve for nodal temperatures in areas with lower temperatures or those that have already cooled; the calculation range can be limited to the area near the heat source. Therefore, at a certain moment during the welding process, mesh cells near the moving heat source are extracted as a local calculation region. Fixed temperature and displacement boundary conditions are set to simulate the heat input and constraints during the welding process, solving for the local temperature field and approximate stress-deformation field at the current time step. Then, the temperature and deformation fields are mapped onto the overall coarse mesh region. Using global structural thermodynamic boundary conditions, iterative calculations of thermal equilibrium and force equilibrium are performed again to obtain the overall welding temperature and deformation fields. Furthermore, by storing the temperature field data at each moment separately, heat conduction and deformation calculations can be performed synchronously at the macroscopic level.

[0056] To address the issues of excessive computational load and long waiting times in existing heat source movement simulations, this invention proposes a mesh-local solution-global mapping technique. This involves designating the region near the heat source as a local computational area on a fine mesh, and dynamically fixing some nodes to reduce degrees of freedom, thus ensuring high-precision solutions for non-fixed regions near the heat source. These solutions are then mapped onto a coarse mesh to obtain the overall temperature and deformation fields, resulting in a thermo-elastic-plastic finite element method with high computational efficiency, low storage space, and a large time step. This gives the thermoplastic finite element method its advantages of high computational efficiency, low storage space, and large time step. Furthermore, to overcome the shortcomings of existing sequential simulations that perform heat conduction analysis first and then stress-strain analysis, this invention proposes a parallel computation method for heat conduction and stress solution modules, eliminating the waiting time in the heat conduction analysis process and further improving simulation efficiency. This invention also relates to an efficient method for calculating temperature and deformation during welding processes, which can be directly applied to the field of welding process simulation technology for metal structures.

[0057] As a preferred embodiment, the present invention is implemented based on the above embodiments. Step S12, namely, obtaining multiple grid cells on the second grid that are currently close to the moving heat source as a local calculation region, includes steps S121 and S122:

[0058] S121. On the second grid of the welding model, the size of the sphere dividing the fixed and non-fixed regions is determined by a one-dimensional heat transfer model; wherein, the fixed region is the region with a lower temperature or that has been cooled at the current moment, and the non-fixed region is the region that is close to the moving heat source at the current moment;

[0059] S122. Divide each grid cell into fixed and non-fixed regions according to the sphere, and use the non-fixed regions as local calculation regions.

[0060] In this embodiment of the invention, taking a first mesh as a coarse mesh and a second mesh as a fine mesh as an example, based on the characteristics of the moving heat source, the fine mesh is used to capture the high temperature gradient and rapidly changing thermal phenomena during the welding simulation. For areas with lower temperatures or that have already cooled, since their thermal impact on the welding process is relatively small, it is not necessary to perform detailed temperature calculations at every node in these areas. The main thermal effects during the welding process are concentrated near the heat source; therefore, limiting the computational scope to the area close to the heat source can significantly reduce the computational load while maintaining accurate simulation of key parts of the welding process. By dynamically fixing some nodes to reduce degrees of freedom, high-precision solutions for non-fixed areas near the heat source are ensured.

[0061] Specifically, the size of the sphere dividing the fixed and non-fixed regions is determined on a fine mesh using a one-dimensional heat transfer model or other methods. For example... Figure 3 The diagram illustrates the principle of calculating the size of the non-fixed region in this embodiment of the invention. The one-dimensional heat transfer model is a simplified heat conduction model used to quickly estimate the thermal influence range. A sphere is determined using the one-dimensional heat transfer model; this sphere is used to divide the fixed and non-fixed regions on the fine mesh. The size of this sphere is determined based on factors such as heat source intensity, material thermal properties, and welding time. The divided non-fixed region serves as the local computational region, which is the focus of subsequent high-precision calculations to reduce computational degrees of freedom.

[0062] Preferably, determining the size of the sphere dividing the fixed and non-fixed regions on the second grid of the welding model using a one-dimensional heat transfer model includes:

[0063] The critical position is calculated based on the initial temperature of the welding model and the preset Gaussian error function; wherein, the critical position is the position where the initial temperature rises to the transient temperature, and the Gaussian error function is used to describe the error of the temperature distribution;

[0064] The radius of the sphere is calculated based on the critical position and the moving speed of the moving heat source.

[0065] Specifically, assuming the initial temperature is T0, the temperature at the wall surface x=0 instantaneously rises to T at t=0. W The temperature at the far-field x = ∞ is fixed at T0. The transient temperature at position x is solved analytically using Eq.1. A Gaussian error function erf(η) is defined to obtain a curve with constant error. By setting η = 2, the error in estimating the critical distance x is ensured to be less than 0.5%, and the relationship between time t and distance is obtained, as shown in Eq.2. For a steady-state heat source, the critical distance between the heat source and the thermal boundary can be calculated directly. If the movement of the heat source is considered, the distance the heat source moves within time t must also be included in the calculation, as shown in Eq.3.

[0066]

[0067] R = x(n,t) inv )+v×t inv (Eq.2)

[0068] Where T0 is the initial ambient temperature, T W Let be the instantaneous highest temperature at the wall edge, 'a' be the thermal diffusivity, 'R' be the radius of the non-fixed region (local calculation region), and 't' be the temperature at the wall edge. inv Let v be the time interval, v be the speed at which the heat source moves, and erf(η) be the Gaussian error function.

[0069] The present invention provides a method for effectively handling fine-grid temperature fields in welding simulation by using the technical means of embodiments of the invention. This method improves computational efficiency and accuracy by dynamically fixing some nodes and limiting the computational range.

[0070] In a preferred embodiment, step S14, mapping the local temperature field of the local calculation region onto the corresponding first grid and calculating the global temperature field of the welding model, includes:

[0071] The heat distribution on the first grid is determined based on the characteristics of the moving heat source, and the initial global temperature field of the welding model is calculated based on heat conduction.

[0072] The local temperature field of the local computational region is mapped onto the first grid to cover the corresponding part of the data in the initial global temperature field, thereby updating the global temperature field of the welding model.

[0073] Preferably, the step of mapping the local temperature field of the local computational region onto the first mesh to cover the corresponding part of the data in the initial global temperature field, and updating the global temperature field of the welding model, includes:

[0074] The normalized coordinates of each node in the first grid corresponding to the second grid are calculated using the Newton-Raphson method.

[0075] Using element shape functions, the temperature value of the node corresponding to the first mesh is calculated by interpolation of the temperature value of the local temperature field in the local computational region. The initial global temperature field is then updated to obtain the global temperature field of the welding model.

[0076] In an embodiment of the present invention, see Figure 4 This is a schematic diagram of the heat source location and local calculation region in an embodiment of the present invention. After determining the local calculation region Ω... F After updating the boundary conditions, a finer mesh is used to solve the local computational domain. Figure 4 The temperature distribution in the vicinity of the heat source is obtained by using the light-shaded area (medium shaded area). At the same time, heat is distributed on the coarse grid according to the characteristics of the heat source, and the global temperature field distribution at each time moment is solved.

[0077] After obtaining two sets of temperature field results for local regions of the welding model—one with a coarse mesh and the other with a fine mesh—the local temperature field of the fine mesh is mapped onto the coarse mesh to obtain a more accurate global temperature field. Compared to existing methods that compute over the entire weld seam with a fine mesh, this approach significantly reduces computational resource requirements and shortens simulation time while maintaining simulation accuracy, making it particularly efficient when dealing with large and complex structures.

[0078] See Figure 5This is a schematic diagram illustrating the principle of mesh mapping in this embodiment of the invention. The specific mapping method is as follows: After obtaining these two sets of temperature field results, an accurate and complete welding temperature field is constructed by mapping the variables between meshes. Due to the structure of the fine and coarse meshes, the topology may not be hierarchical, making it impossible to use a single interpolation function. Therefore, a raw data mapping method applicable to any mesh structure is adopted. The specific steps of the mesh mapping process are as follows: the normalized coordinates of each node in the coarse mesh corresponding to the fine mesh are calculated using the Newton-Raphson method, as shown in Eq.4; the temperature of the nodes in the coarse mesh is calculated by interpolating the temperature values ​​in the fine mesh using the element shape function, as shown in Eq.5. Since the solution is only performed on the coarse mesh and local areas of the fine mesh, the computational efficiency of the new method for simulating arc welding is improved by several times compared to conventional algorithms.

[0079] In a preferred embodiment, step S14, mapping the local stress of the local calculation region onto the corresponding first mesh and calculating the overall stress of the welding model, includes:

[0080] The local stress of the local calculation region is mapped to the first mesh for overall stress balance calculation to obtain the overall stress of the welding model.

[0081] Structural deformation and stress are simulated in a local computational region using a fine mesh, and then mapped to a coarse mesh region for overall stress balance calculation. Specifically, nodes in the coarse mesh are located on the fine mesh to obtain their canonical coordinates (ξ, η, ζ) relative to the target element. Then, interpolation is performed using the element's shape function to obtain the deformation of the coarse mesh nodes, as shown in Eq. 6. Similarly, the integration points of the coarse mesh are projected onto the fine mesh, and the canonical coordinates of the corresponding integration point positions are obtained through inverse solving, yielding the stress and strain at the integration points of the coarse mesh, as shown in Eq. 7. See also... Figure 6 This is a schematic diagram illustrating the principle of solving welding deformation in an embodiment of the present invention. The specific analysis of the deformation at the position of the element node is as follows: Figure 6 As shown, after obtaining two sets of temperature field results, the simulation results of the local area of ​​the fine mesh are mapped to the coarse mesh, and then the thermo-elastic-plastic analysis of the overall structure is performed. Figure 6 for Figure 4 The calculation process for welding heat conduction and deformation analysis using two types of meshes with different coarse and fine meshes is as follows: For example, in the heat conduction analysis of arc welding, the heat source location X(x,y,z,t) and the basic heat flow distribution Q(x,y,z,t) are first defined, and then the temperature field calculations of the overall model and local regions are performed on the coarse and fine meshes respectively.

[0082]

[0083] T C (x,y,z)=∑Ni (x,y,z)T Fi (Eq.5)

[0084] U C (x,y,z)=∑N i (x,y,z)U Fi (Eq.6)

[0085] S C (x,y,z)=∑N i (x,y,z)S Fi (Eq.7)

[0086] Where, N i Let ξ be the i-th component of the unit shape function. i η i ζ i Let T be the node regularized coordinates (values ​​±1), ξ, η, and ζ be the regularized coordinate components of the spatial location point relative to the element (corresponding to the x, y, and z directions in 3D space), and T be the coordinates of the node. C Let T be the temperature at a point (x, y, z) in the coarse grid space. Fi U represents the temperature value of node i in the fine mesh. C For the deformation of a point (x,y,z) in a coarse mesh space, U Fi S represents the deformation of node i in the fine mesh. C Let S be the stress at a point (x,y,z) in a coarse-grid space. Fi Let be the stress value at integration point i in the fine mesh.

[0087] Then, following the same method, the heat source was moved to the next moment for heat conduction analysis and elastoplastic mechanical analysis until the welding was completed and the structure cooled to room temperature, finally obtaining the deformation of the overall structure.

[0088] By employing the technical means of this invention, rapid welding simulation based on local and global mesh mapping is achieved, which can efficiently obtain the deformation of the overall welded structure and effectively reduce the computational load in the welding simulation process.

[0089] The embodiments of the present invention will be further explained and illustrated below through specific implementation scenarios.

[0090] like Figure 6As shown, the welding heat conduction and deformation calculation according to the embodiment of the present invention adopts a sequentially coupled analysis step. First, heat conduction analysis is performed on the local region of the fine mesh and the overall model of the coarse mesh to obtain the welding temperature field of the structure. Then, the temperature field is mapped and synthesized to form a welding temperature field that meets the temperature gradient requirements near the weld. In this embodiment, the coarse and fine meshes of the welding model are established, each occupying the same geometric space of the welding structure, and there is no topological interconnection between the meshes. Two identical heat sources move in the coarse and fine mesh models respectively, and the heat source parameters include welding power, heat source size, and moving speed. The mesh type can be a two-dimensional plane or a three-dimensional solid element, and there is no limitation on the number of nodes in the element. At a certain moment (e.g., t1), the area affected by the heat source is as follows: Figure 4 As shown in the dark area of ​​the coarse mesh, heat conduction calculations are performed on the overall coarse mesh model, and the temperature field at that moment is denoted as T. C Meanwhile, in a fine mesh, elements close to the heat source will constitute the local solution domain. Figure 4 The dark regions of the medium-fine mesh are excluded from the calculation, while the remaining meshes are not included. A fixed temperature is set at the boundaries. The temperature field obtained from solving the local region of the fine mesh is denoted as T. F The temperature result T of this local area is calculated with high accuracy. F Mapping to a coarse mesh to cover T C From some of the data, we obtained new temperature field calculation results T. B Variable transfer between coarse and fine meshes is achieved through interpolation using element shape functions. After calculating the overall temperature field, thermo-elastic-plastic finite element analysis is performed based on the local model of the fine mesh. Displacement constraints are applied to the boundaries of the local region, and an approximate displacement field is obtained through rapid iteration. This approximate displacement field is then mapped to the coarse mesh model for stress calculation of the overall model. In the above welding heat conduction and elastoplastic calculations, temperature and displacement between the coarse and fine meshes are mapped using interpolation functions. After each mesh model has been solved, the next time step involves region selection and calculation. This embodiment of the invention also supports using the mapped and synthesized temperature field to directly calculate the stress of the coarse mesh model, achieving efficient welding simulation.

[0091] Of course, this welding simulation method based on meshes of varying coarseness can also be applied to strongly coupled thermo-mechanical calculation models, simultaneously obtaining temperature and deformation within a single time step. Furthermore, the mapping direction between coarse and fine meshes is not limited to fine-to-coarse; a coarse-to-fine mesh approach can also be used, followed by local or global stress-deformation calculations based on the fine mesh. The selection of the local computational region for the fine mesh can include, but is not limited to, rectangles, spheres, ellipsoids, or other suitable shapes.

[0092] See Figure 7This is a schematic diagram of the structure of a welding simulation device provided in an embodiment of the present invention. The present invention also provides a welding simulation device 10, comprising:

[0093] The mesh generation module 11 is used to mesh the welding model using a first mesh and a second mesh, respectively; wherein the first mesh and the second mesh are of different sizes.

[0094] The local computational region acquisition module 12 is used to acquire multiple grid cells on the second grid that are close to the moving heat source at the current moment as local computational regions;

[0095] The local calculation region calculation module 13 is used to set boundary conditions with fixed temperature and displacement in the local calculation region in order to calculate the local temperature field and local stress deformation field of the local calculation region.

[0096] Mesh mapping module 14 is used to map the local temperature field and local stress of the local calculation region onto the corresponding first mesh, and calculate the global temperature field and overall stress of the welding model respectively.

[0097] The welding deformation acquisition module 15 is used to obtain the welding deformation of the welding model based on the global temperature field and overall stress of the welding model at various times during the welding process.

[0098] This invention proposes a mesh-based local solution-global mapping technique. On a fine mesh, the region near the heat source is designated as the local computational domain. By dynamically fixing some nodes to reduce degrees of freedom, high-precision solutions for the non-fixed region near the heat source are guaranteed. This solution is then mapped onto a coarse mesh to obtain the global temperature and deformation fields, thus forming a thermo-elastic-plastic finite element method with high computational efficiency, low storage space, and large time step. This gives the thermoplastic finite element method its advantages of high computational efficiency, low storage space, and large time step. Simultaneously, a collaborative parallel computation method for heat conduction and stress solution modules is proposed, eliminating the waiting time in the heat conduction analysis process and further improving simulation efficiency. This invention relates to an efficient method for calculating temperature and deformation during welding processes and can be directly applied to the field of welding process simulation technology for metal structures.

[0099] It should be noted that the welding simulation device provided in this embodiment of the invention is used to execute all the process steps of the welding simulation method in the above embodiment. The working principle and beneficial effects of the two are one-to-one, so they will not be described again.

[0100] This invention also provides a welding simulation device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the welding simulation method as described in any of the above embodiments.

[0101] This invention also provides a computer-readable storage medium, which includes a stored computer program, wherein the computer program, when running, controls the device where the computer-readable storage medium is located to execute the welding simulation method as described in any of the above embodiments.

[0102] This invention also provides a computer program product, which includes a computer program or computer instructions. When the computer program or computer instructions are executed by a processor, they implement the welding simulation method as described in any of the above embodiments.

[0103] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0104] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A welding simulation method, characterized in that, include: The welding model is meshed using a first mesh and a second mesh, respectively; wherein the first mesh and the second mesh are of different sizes. Obtain multiple grid cells on the second grid that are currently close to the moving heat source as a local computational region; Boundary conditions with fixed temperature and displacement are set in the local calculation region to calculate the local temperature field and local stress-deformation field of the local calculation region. The local temperature field and local stress of the local calculation region are mapped onto the corresponding first grid, and the global temperature field and overall stress of the welding model are calculated respectively. Based on the global temperature field and overall stress of the welding model at various times during the welding process, the welding deformation of the welding model is obtained.

2. The welding simulation method as described in claim 1, characterized in that, The step of obtaining multiple grid cells on the second grid that are currently close to the moving heat source as a local computational region includes: On the second grid of the welding model, the size of the spheres dividing the fixed and non-fixed regions is determined by a one-dimensional heat transfer model; wherein, the fixed region is the region with a lower temperature or that has been cooled at the current moment, and the non-fixed region is the region that is close to the moving heat source at the current moment; The sphere is used to divide each grid cell into fixed and non-fixed regions, and the non-fixed regions are used as local computational regions.

3. The welding simulation method as described in claim 2, characterized in that, The determination of the sphere size for dividing the fixed and non-fixed regions on the second grid of the welding model using a one-dimensional heat transfer model includes: The critical position is calculated based on the initial temperature of the welding model and the preset Gaussian error function; wherein, the critical position is the position where the initial temperature rises to the transient temperature, and the Gaussian error function is used to describe the error of the temperature distribution; The radius of the sphere is calculated based on the critical position and the moving speed of the moving heat source.

4. The welding simulation method as described in claim 1, characterized in that, The step of mapping the local temperature field of the local computational region onto the corresponding first grid and calculating the global temperature field of the welding model includes: The heat distribution on the first grid is determined based on the characteristics of the moving heat source, and the initial global temperature field of the welding model is calculated based on heat conduction. The local temperature field of the local computational region is mapped onto the first grid to cover the corresponding part of the data in the initial global temperature field, thereby updating the global temperature field of the welding model.

5. The welding simulation method as described in claim 4, characterized in that, The step of mapping the local temperature field of the local computational region onto the first grid to cover the corresponding part of the data in the initial global temperature field and updating the global temperature field of the welding model includes: The normalized coordinates of each node in the first grid corresponding to the second grid are calculated using the Newton-Raphson method. Using element shape functions, the temperature value of the node corresponding to the first mesh is calculated by interpolation of the temperature value of the local temperature field in the local computational region. The initial global temperature field is then updated to obtain the global temperature field of the welding model.

6. The welding simulation method as described in claim 1, characterized in that, The step of mapping the local stress of the local computational region onto the corresponding first mesh and calculating the overall stress of the welding model includes: The local stress of the local calculation region is mapped to the first mesh for overall stress balance calculation to obtain the overall stress of the welding model.

7. A welding simulation device, characterized in that, include: The mesh generation module is used to divide the welding model into a first mesh and a second mesh, respectively; wherein the first mesh and the second mesh are of different sizes. The local computational region acquisition module is used to acquire multiple grid cells on the second grid that are close to the moving heat source at the current moment as local computational regions; The local calculation region calculation module is used to set boundary conditions with fixed temperature and displacement in the local calculation region in order to calculate the local temperature field and local stress deformation field of the local calculation region. The mesh mapping module is used to map the local temperature field and local stress of the local calculation region onto the corresponding first mesh, and to calculate the global temperature field and overall stress of the welding model respectively. The welding deformation acquisition module is used to obtain the welding deformation of the welding model based on the global temperature field and overall stress of the welding model at various times during the welding process.

8. A welding simulation device, characterized in that, It includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the welding simulation method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored computer program, wherein, when the computer program is executed, it controls the device on which the computer-readable storage medium is located to perform the welding simulation method as described in any one of claims 1 to 6.

10. A computer program product, characterized in that, The computer program product includes a computer program or computer instructions, which, when executed by a processor, implement the welding simulation method as described in any one of claims 1 to 6.

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