A solder joint failure analysis method, device and product

Abstract

The embodiment of the application provides a welding point failure analysis method, device and product. The welding point failure analysis method performs time accumulation of plastic strain energy on a second area of an indication heat affected zone of a welding point model in a loading process, accurately locks the area which is most affected by welding heat cycle and has the weakest material performance in the welding point structure. Since the energy accumulation process of the heat affected zone can truly reflect the continuous effect of the load and the destructive potential, compared with the prior art which only judges according to the instantaneous stress or force state, the scheme helps to solve the failure analysis behaviors of "instantaneous overload not broken" and "long-term creep fracture", and improves the welding point failure analysis.

Description

Technical Field

[0001] This application relates to the field of automotive technology, and in particular to a method, apparatus and product for analyzing weld joint failures. Background Technology

[0002] In automotive structures, weld joints are one of the primary connection methods. Analyzing the failure behavior of weld joints is crucial for the safety and durability of the entire vehicle. Current weld joint failure analysis methods mainly rely on stress, resultant force, or strain as the basis for judgment. However, in actual engineering, there are situations where the instantaneous force is very large but the duration of the force is extremely short. In such cases, the weld joint does not fail. Furthermore, there are also some weld joints that fail despite relatively small instantaneous forces. Therefore, providing a new weld joint failure analysis method to improve the accuracy of weld joint failure analysis has become a technical problem to be solved. Summary of the Invention

[0003] This application provides a solder joint failure analysis method, apparatus, and product that can accurately analyze the failure behavior of solder joints.

[0004] In a first aspect, embodiments of this application provide a solder joint failure analysis method to obtain a solder joint model of the solder joint to be analyzed; The weld joint model includes a first region and a second region. The first region indicates the weld nugget of the weld joint to be analyzed, and the second region indicates the heat-affected zone of the weld joint to be analyzed. The heat-affected zone is the area of ​​the weld joint to be analyzed that is affected by thermal cycling during the welding process, where the material properties change but the weld joint does not melt. The weld joint model is loaded, and during the loading process, the cumulative plastic strain energy of the second region is determined; wherein the cumulative plastic strain energy indicates the plastic strain energy accumulated over time during the loading process; If the cumulative plastic strain energy in the second region is greater than or equal to the strain energy threshold, the heat-affected zone is determined to be in failure.

[0005] Optionally, the weld joint model is a mesh model, and determining the cumulative plastic strain energy of the second region includes: Determine the cumulative plastic strain energy at each integration point in the second region; The step of determining the failure of the heat-affected zone if the accumulated plastic strain energy in the second region is greater than or equal to the strain energy threshold includes: If the accumulated plastic strain energy at at least one integration point is greater than or equal to the strain energy threshold, the heat-affected zone is determined to be in failure.

[0006] Optionally, the method further includes: Delete the failure unit in the second region; the failure unit indicates the integration point where the accumulated plastic strain energy is greater than or equal to the strain energy threshold.

[0007] Optionally, the method further includes: If the cumulative plastic strain energy at all integration points is less than the strain energy threshold, the heat-affected zone is determined to be unfailed.

[0008] Optionally, the method for determining the strain energy threshold includes: determining the strain energy threshold by integrating the actual stress-strain curve of the material in the heat-affected zone.

[0009] Optionally, the solder joint model is a mesh model, and the solder joint model further includes a third region located around the second region. The method further includes: During the loading process, the ratio between the plastic strain energy of the second region and the plastic strain energy of the third region is monitored in real time. If the ratio is greater than or equal to the gradient threshold, adaptive mesh re-division is performed on the second region and the third region, wherein the second region uses the first mesh and the third region uses the second mesh, and the mesh size of the first mesh is smaller than the mesh size of the second mesh.

[0010] Optionally, the second region is modeled based on the actual size of the heat-affected zone in the weld joint to be analyzed; multiple first regions are connected by rigid bodies.

[0011] Secondly, embodiments of this application provide a solder joint failure analysis device, the device comprising: The acquisition unit is used to acquire the solder joint model of the solder joint to be analyzed. The weld joint model includes a first region and a second region. The first region indicates the weld nugget of the weld joint to be analyzed, and the second region indicates the heat-affected zone of the weld joint to be analyzed. The heat-affected zone is the area of ​​the weld joint to be analyzed that is affected by thermal cycling during the welding process, where the material properties change but the weld joint does not melt. A loading calculation unit is used to load the weld joint model and, during the loading process, determine the cumulative plastic strain energy of the second region; wherein, the cumulative plastic strain energy indicates the plastic strain energy accumulated over time during the loading process; The judgment unit is used to determine that the heat-affected zone fails if the accumulated plastic strain energy of the second region is greater than or equal to the strain energy threshold.

[0012] Thirdly, embodiments of this application also provide a computer-readable storage medium having a computer program stored thereon, which, when run on a computer, causes the computer to perform any of the possible methods described in the first aspect.

[0013] Fourthly, embodiments of this application also provide a computer program product that, when run on a computer, executes the method as described in any of the first aspects.

[0014] Fifthly, embodiments of this application provide a computing device, which includes a memory and a processor; the memory and the processor are coupled together. The memory is used to store program instructions; the processor is used to invoke the program instructions to cause the computing device to perform the method as described in any of the first aspects.

[0015] Beneficial effects: This application provides a method, apparatus, and product for analyzing weld joint failure. The method includes: acquiring a weld joint model of the weld joint to be analyzed; wherein the weld joint model includes a first region and a second region, the first region indicating the weld nugget of the weld joint to be analyzed, and the second region indicating the heat-affected zone (HAZ) of the weld joint to be analyzed, the HAZ being the area where the material properties of the weld joint change due to thermal cycling during welding, but which has not melted; loading the weld joint model, and during the loading process, determining the cumulative plastic strain energy of the second region; wherein the cumulative plastic strain energy indicates the plastic strain energy accumulated over time during the loading process; if the accumulated plastic strain energy of the second region is greater than or equal to a strain energy threshold, heat-affected zone failure is determined.

[0016] This method accurately identifies the region in the weld joint structure that is most affected by the welding thermal cycle and has the weakest material properties by accumulating the plastic strain energy over time in the second zone of the indicated heat-affected zone of the weld joint model during loading. Since the energy accumulation process in the heat-affected zone can truly reflect the sustained effect of the load and the destructive potential energy, compared to existing technologies that rely solely on instantaneous stress or force states, this approach helps to address the failure analysis behaviors of "instantaneous overload without failure" and "long-term creep fracture," thus improving weld joint failure analysis. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of a solder joint structure provided as an example in this application; Figure 2 A flowchart of the solder joint failure analysis method provided in the embodiments of this application; Figure 3 A schematic diagram of a solder joint model provided in an embodiment of this application; Figure 4 This is a schematic diagram of a solder joint failure analysis device provided in an embodiment of this application. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0020] Weld joints are a primary connection method in automobile body manufacturing. The welding quality of these joints directly determines the overall rigidity and crash safety of the vehicle body. Therefore, it is necessary to analyze the failure behavior of weld joints.

[0021] Appendix Figure 1 This is a schematic diagram illustrating a solder joint structure as an example of this application. Figure 1 As shown, the weld joint includes, from the inside out, a weld nugget 101 and a heat-affected zone (HAZ) 102 surrounding the weld nugget. Additionally, the weld joint may include a base material area 103 located outside the HAZ.

[0022] Among them, the weld nugget 101 is located at the very center of the weld joint. During the welding process, pressure and current are applied to the electrodes, causing the two or more layers of metal plates to melt locally at the contact surface and form a molten pool. After cooling, it solidifies to form a weld nugget, which has a relatively high hardness.

[0023] The heat-affected zone 102 is located around the weld nugget 101. The metal in this region has undergone welding thermal cycling; although it has not melted, its microstructure and mechanical properties (such as strength and ductility) have undergone irreversible changes due to heat. The heat-affected zone is the weakest and most prone to failure area in the weld joint structure.

[0024] Due to the different heating temperatures, the heat-affected zones exhibit significant microstructural differences along the radial direction (from near to far from the weld nugget). Specifically, the heat-affected zones, from the inside out, include: a coarse-grain heat-affected zone (CGHAZ), a fine-grain heat-affected zone (FGHAZ), an intercritical heat-affected zone (ICHAZ), and a subcritical heat-affected zone (SCHAZ).

[0025] CGHAZ, also known as the overheated zone or fusion zone, is located immediately after the weld nugget's fusion line. It is heated to extremely high temperatures (usually above 1100℃~1300℃), causing austenite grains to grow rapidly. After cooling, it forms a coarse and brittle structure (such as martensite), which is the main area for weld joint failure.

[0026] FGHAZ, also known as the normalized zone, is located outside the CGHAZ. It is heated at a moderate temperature (usually between 900℃ and 1100℃), which is equivalent to undergoing a normalizing heat treatment. The microstructure recrystallizes and the grains are refined, resulting in relatively good mechanical properties. It is the least likely area to fail in the heat-affected zone.

[0027] ICHAZ, also known as the partial phase transition zone, is located outside the FGHAZ. Heated at temperatures in the two-phase region (typically 700℃~900℃), only a portion of the microstructure undergoes a phase transition, resulting in uneven microstructure and properties.

[0028] SCHAZ is located outside ICHAZ. It is heated to a temperature lower than the phase transformation temperature (usually <700℃). The microstructure does not undergo phase transformation, but only tempering or aging effects occur. The properties change little, serving as a transition zone between the heat-affected zone and the base material.

[0029] Related technologies often rely on stress, resultant force, or strain as the basis for judgment, assuming that extremely high stress, resultant force, or strain will lead to solder joint failure. However, stress, resultant force, or strain are all instantaneous forces, with a very short duration or a very small number of applications. In one scenario, a large instantaneous force may not cause solder joint failure. In another scenario, a relatively small instantaneous force, but with a long cumulative duration or numerous applications, can also lead to solder joint failure.

[0030] In view of this, this application provides a weld joint failure analysis method. By accumulating the plastic strain energy over time in the second zone of the heat-affected zone (HAZ) of the weld joint model during loading, the method accurately identifies the region in the weld joint structure that is most affected by the welding thermal cycle and has the weakest material properties. Since the energy accumulation process in the HAZ can truly reflect the sustained effect of the load and the destructive potential energy, compared with the prior art which only judges based on the state of instantaneous stress or force, this solution helps to solve the failure analysis behaviors of "instantaneous overload failure" and "long-term creep fracture," thus improving the weld joint failure analysis.

[0031] The solder joint failure analysis method provided in this application can be applied to a failure analysis system. The failure analysis system can be a computing device, other electronic devices with computing capabilities, or a software platform or hardware functional module within an electronic device. This application is not limited in its implementation.

[0032] Specifically, the failure analysis system is used to: acquire a weld model of the weld to be analyzed; wherein the weld model includes a first region and a second region, the first region indicating the weld nugget of the weld to be analyzed, and the second region indicating the heat-affected zone of the weld to be analyzed, the heat-affected zone being the area of ​​the weld to be analyzed that has undergone changes in material properties due to thermal cycling during the welding process, but has not melted; load the weld model, and during the loading process, determine the cumulative plastic strain energy of the second region; wherein the cumulative plastic strain energy indicates the plastic strain energy accumulated over time during the loading process; if the cumulative plastic strain energy of the second region is greater than or equal to the strain energy threshold, the heat-affected zone is determined to be a failure.

[0033] The following is in conjunction with the appendix Figure 2 ~Appendix Figure 3 The following describes the solder joint failure analysis method provided in the embodiments of this application. (See attached diagram.) Figure 2 A flowchart illustrating the solder joint failure analysis method provided in this application embodiment. (Attached) Figure 3 This is a schematic diagram of a solder joint model provided in an embodiment of this application.

[0034] like Figure 2 As shown, the method includes the following steps: S10, the failure analysis system acquires the solder joint model of the solder joint to be analyzed.

[0035] It should be noted that the solder joint failure analysis method provided in this application embodiment is a solder joint simulation failure analysis method. First, a solder joint model of the solder joint to be analyzed needs to be constructed so as to perform failure simulation analysis through the solder joint model.

[0036] This application provides a solder joint model, which includes a first region and a second region. The first region indicates the weld nugget of the solder joint to be analyzed, and the second region indicates the heat-affected zone of the solder joint to be analyzed.

[0037] In practical applications, the weld nugget has high hardness, and weld nugget failure is rare; the main area of ​​failure is the heat-affected zone (HAZ). Therefore, in one example, the weld nuggets in the first zone can be rigidly connected. The second zone can be modeled based on the actual dimensions of the HAZ and the welding process. Determining the dimensions of the second zone based on the actual welding process (such as the current, pressure, and time in resistance spot welding), rather than using idealized geometric assumptions, allows for a more realistic simulation of the impact of microstructural changes on macroscopic mechanical properties during the welding process, further improving the fidelity of the simulation model.

[0038] Furthermore, the weld joint model may also include a third region, which is located within the second region cycle. The third region indicates the base material region.

[0039] In one example, the solder joint model can be a mesh model.

[0040] In another example, in order to reduce the dependence of the welding spot model on meshes, realize automatic increase of mesh density in the region with sharp energy change (the second region) to ensure accuracy, and sparse mesh density in the region with gentle energy change (the third region) to improve calculation efficiency, the embodiments of the present application further provide an adaptive mesh adjustment scheme. Specifically, during the loading process, the ratio between the plastic strain energy of the second region and the plastic strain energy of the first region is monitored in real time; if the ratio is greater than or equal to the gradient threshold, a first mesh is used in the second region, and a second mesh is used in the third region. The mesh size of the first mesh is different from that of the second mesh, and the mesh size of the first mesh is smaller than that of the second mesh. For example, the gradient threshold is 3. By monitoring the energy gradient between the heat affected zone and the base material zone, adaptive mesh refinement is realized, thereby reducing the calculation cost while ensuring calculation accuracy.

[0041] In another example, in order to further reduce the dependence of the welding spot model on mesh size and improve calculation efficiency while ensuring calculation accuracy, an adaptive mesh adjustment scheme is provided. Specifically, during the loading process, the ratio R of the cumulative plastic strain energy of the second region to that of the third region is monitored in real time. If R is greater than or equal to a preset gradient threshold, the mesh sizes of the second region and the third region are dynamically adjusted according to the value of R. Wherein, the mesh size d1 of the second region is inversely proportional to R, that is, the larger the ratio is, the smaller the mesh size of the second region is, so as to more accurately capture the plastic deformation behavior in the energy concentration region; the third region adopts a relatively larger mesh size to reduce the overall calculation amount.

[0042] In a specific example, the mesh size of the second region satisfies: d1=d0 / R, wherein d0 is a reference mesh size. In another example, when 3≤R<n1, the mesh size of the second region is 1 / 2 of that of the third region; when R≥n1, the mesh size of the second region is 1 / 4 of that of the third region. Wherein, n1 is an integer greater than 3, for example, n1 is 6. Other adaptive mesh control methods may also be adopted in the embodiments of the present application, which is not limited in the present application.

[0043] For ease of understanding, the accompanying Figure 3 provides a welding spot model, which includes five first regions 301, five second regions 302 and a third region 303.

[0044] Rigid connection is adopted between a plurality of first regions 301. The second region 302 is modeled according to the actual size of the heat affected zone, and the size of the heat affected zone is generally 1-2 mm.

[0045] S20, loading the welding spot model, and determining the cumulative plastic strain energy of the second region during the loading process.

[0046] In this embodiment, loading the weld joint model refers to applying tensile, compressive, or combined loads consistent with its service environment to the weld joint model in a finite element simulation environment, based on actual engineering conditions (such as vehicle collision, structural durability, etc.), and applying corresponding boundary constraints. This loading process can be discretized according to the time step to simulate the real load-time history.

[0047] During the loading process, the failure analysis system can perform cumulative calculations of the plastic strain energy in the second zone to obtain the cumulative plastic strain energy in the second zone.

[0048] In one implementation, the failure analysis system specifically calculates the cumulative plastic strain energy at each integration point in the second region. The cumulative plastic strain energy in the second region indicates the cumulative plastic strain energy at each integration point within the second region.

[0049] For each integration point, the cumulative plastic strain energy at that point can be determined as follows. This method includes the following steps: Within each time step, the increment of plastic strain energy is determined based on the stress tensor and the increment of plastic strain at the integration point. Over a preset duration, the increment of plastic strain energy is accumulated to obtain the cumulative plastic strain energy at that integration point.

[0050] By accumulating energy at the integration point level, this invention can accurately capture the local energy dissipation process within the heat-affected zone, avoiding the omission of local damage due to regional averaging, thereby significantly improving the accuracy of simulation calculations and the reliability of failure prediction.

[0051] S30, determine whether the cumulative plastic strain energy in the second region is greater than or equal to the strain energy threshold.

[0052] In this embodiment, the strain energy threshold can be determined based on the integral of the actual stress-strain curve of the material in the heat-affected zone to ensure the scientific validity and feasibility of the failure criterion.

[0053] In one specific implementation, quasi-static or dynamic tensile tests can be performed on the heat-affected zone material to obtain its true stress-strain curves at different strain rates. By integrating this stress-strain curve from zero strain to the material's fracture strain, the maximum plastic strain energy that a unit volume of material can absorb before failure is obtained. This maximum plastic strain energy is the strain energy threshold.

[0054] The failure analysis system can determine whether the heat-affected zone has failed by using the relationship between the accumulated plastic strain energy in the second zone and the strain energy threshold.

[0055] S40, if the cumulative plastic strain energy in the second zone is greater than or equal to the strain energy threshold, the heat-affected zone is determined to be in failure.

[0056] Specifically, if the cumulative plastic strain energy at at least one integration point in the second region is greater than or equal to the strain energy threshold, the second region is determined to be in failure.

[0057] Furthermore, for the heat-affected zone (HAZ) after failure, the failure elements within that HAZ can be deleted. A failure element is an integration point where the accumulated plastic strain energy is greater than or equal to the strain energy threshold. By deleting failure elements, the initiation and propagation process of cracks can be realistically simulated, reflecting the structural response after weld failure.

[0058] S50, if the cumulative plastic strain energy in the second zone is less than the strain energy threshold, the heat-affected zone is determined to be unfailed.

[0059] Specifically, if the cumulative plastic strain energy at all integration points in the second region is less than the strain energy threshold, the second region is determined to be not in failure.

[0060] The weld joint failure analysis method includes: acquiring a weld joint model of the weld joint to be analyzed; wherein the weld joint model includes a first region and a second region, the first region indicating the weld nugget of the weld joint to be analyzed, and the second region indicating the heat-affected zone (HAZ) of the weld joint to be analyzed, the HAZ being the area of ​​the weld joint to be analyzed where the material properties have changed due to thermal cycling during the welding process, but which has not melted; loading the weld joint model, and determining the cumulative plastic strain energy of the second region during the loading process; wherein the cumulative plastic strain energy indicates the plastic strain energy accumulated over time during the loading process; if the cumulative plastic strain energy of the second region is greater than or equal to the strain energy threshold, the HAZ is determined to be a failure. This method, by accumulating the plastic strain energy over time in the second region of the weld joint model indicating the HAZ during the loading process, accurately identifies the region in the weld joint structure that is most affected by welding thermal cycling and has the weakest material properties. Since the energy accumulation process in the heat-affected zone can truly reflect the sustained effect of the load and the destructive potential energy, compared with the existing technology that only judges based on the state of instantaneous stress or force, this solution helps to solve the failure analysis behavior of "instantaneous overload failure" and "long-term creep fracture", and improves the failure analysis of weld joints.

[0061] Furthermore, this application also provides a solder joint failure analysis device that applies the above-described method.

[0062] Appendix Figure 4 This is a schematic diagram of a solder joint failure analysis device provided in an embodiment of this application. The device 400 includes: Acquisition unit 401 is used to acquire the weld joint model of the weld joint to be analyzed; The weld joint model includes a first region and a second region. The first region indicates the weld nugget of the weld joint to be analyzed, and the second region indicates the heat-affected zone of the weld joint to be analyzed. The heat-affected zone is the area of ​​the weld joint to be analyzed that is affected by thermal cycling during the welding process, where the material properties change but the weld joint does not melt. The loading calculation unit 402 is used to load the weld joint model and determine the cumulative plastic strain energy of the second region during the loading process; wherein the cumulative plastic strain energy indicates the plastic strain energy accumulated over time during the loading process; The judgment unit 403 is used to determine that the heat-affected zone fails if the accumulated plastic strain energy of the second region is greater than or equal to the strain energy threshold.

[0063] Optionally, the weld joint model is a mesh model, and determining the cumulative plastic strain energy of the second region includes: Determine the cumulative plastic strain energy at each integration point in the second region; The step of determining the failure of the heat-affected zone if the accumulated plastic strain energy in the second region is greater than or equal to the strain energy threshold includes: If the accumulated plastic strain energy at at least one integration point is greater than or equal to the strain energy threshold, the heat-affected zone is determined to be in failure.

[0064] Optionally, the device 400 further includes a deletion unit for deleting failure units in the second region; the failure units indicate the integration point where the accumulated plastic strain energy is greater than or equal to the strain energy threshold.

[0065] Optionally, the judgment unit 403 is further configured to determine that the heat-affected zone has not failed if the cumulative plastic strain energy of all integration points is less than the strain energy threshold.

[0066] Optionally, the method for determining the strain energy threshold includes: determining the strain energy threshold by integrating the actual stress-strain curve of the material in the heat-affected zone.

[0067] Optionally, the solder joint model is a mesh model, and the solder joint model further includes a third region located around the second region. The acquisition unit 401 is further configured to: During the loading process, the ratio between the plastic strain energy of the second region and the plastic strain energy of the third region is monitored in real time. If the ratio is greater than or equal to the gradient threshold, adaptive mesh re-division is performed on the second region and the third region, wherein the second region uses the first mesh and the third region uses the second mesh, and the mesh size of the first mesh is smaller than the mesh size of the second mesh.

[0068] Optionally, the second region is modeled based on the actual size of the heat-affected zone in the weld joint to be analyzed; multiple first regions are connected by rigid bodies.

[0069] The weld joint failure analysis device provided in this application can accurately pinpoint the area in the weld joint structure that is most affected by the welding thermal cycle and has the weakest material properties by accumulating the plastic strain energy over time in the second zone of the indicated heat-affected zone of the weld joint model during loading. Since the energy accumulation process in the heat-affected zone can truly reflect the sustained effect of the load and the destructive potential energy, compared to existing technologies that rely solely on the state of instantaneous stress or force, it helps to solve the failure analysis behaviors of "instantaneous overload without failure" and "long-term creep fracture," thus improving weld joint failure analysis.

[0070] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for the device and equipment embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiments. The device and equipment embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components indicated as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of the solution in this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0071] The above description is merely one specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for analyzing solder joint failure, characterized in that, The method includes: Obtain the solder joint model of the solder joint to be analyzed; The weld joint model includes a first region and a second region. The first region indicates the weld nugget of the weld joint to be analyzed, and the second region indicates the heat-affected zone of the weld joint to be analyzed. The heat-affected zone is the area of ​​the weld joint to be analyzed that is affected by thermal cycling during the welding process, where the material properties change but the weld joint does not melt. The weld joint model is loaded, and during the loading process, the cumulative plastic strain energy of the second region is determined; wherein the cumulative plastic strain energy indicates the plastic strain energy accumulated over time during the loading process; If the cumulative plastic strain energy in the second region is greater than or equal to the strain energy threshold, the heat-affected zone is determined to be in failure.

2. The method according to claim 1, characterized in that, The weld joint model is a mesh model, and determining the cumulative plastic strain energy of the second region includes: Determine the cumulative plastic strain energy at each integration point in the second region; The step of determining the failure of the heat-affected zone if the accumulated plastic strain energy in the second region is greater than or equal to the strain energy threshold includes: If the accumulated plastic strain energy at at least one integration point is greater than or equal to the strain energy threshold, the heat-affected zone is determined to be in failure.

3. The method according to claim 2, characterized in that, The method further includes: Delete the failure unit in the second region; the failure unit indicates the integration point where the accumulated plastic strain energy is greater than or equal to the strain energy threshold.

4. The method according to claim 2, characterized in that, The method further includes: If the cumulative plastic strain energy at all integration points is less than the strain energy threshold, the heat-affected zone is determined to be unfailed.

5. The method according to claim 1, characterized in that, The method for determining the strain energy threshold includes: determining the strain energy threshold by integrating the actual stress-strain curve of the material in the heat-affected zone.

6. The method according to claim 1, characterized in that, The solder joint model is a mesh model, and the solder joint model also includes a third region located around the second region. The method further includes: During the loading process, the ratio between the plastic strain energy of the second region and the plastic strain energy of the third region is monitored in real time. If the ratio is greater than or equal to the gradient threshold, adaptive mesh re-division is performed on the second region and the third region, wherein the second region uses the first mesh and the third region uses the second mesh, and the mesh size of the first mesh is smaller than the mesh size of the second mesh.

7. The method according to claim 1, characterized in that, The second region is modeled based on the actual size of the heat-affected zone in the weld joint to be analyzed; multiple first regions are connected by rigid bodies.

8. A solder joint failure analysis device, characterized in that, The device includes: The acquisition unit is used to acquire the solder joint model of the solder joint to be analyzed. The weld joint model includes a first region and a second region. The first region indicates the weld nugget of the weld joint to be analyzed, and the second region indicates the heat-affected zone of the weld joint to be analyzed. The heat-affected zone is the area of ​​the weld joint to be analyzed that is affected by thermal cycling during the welding process, where the material properties change but the weld joint does not melt. A loading calculation unit is used to load the weld joint model and, during the loading process, determine the cumulative plastic strain energy of the second region; wherein, the cumulative plastic strain energy indicates the plastic strain energy accumulated over time during the loading process; The judgment unit is used to determine that the heat-affected zone fails if the accumulated plastic strain energy of the second region is greater than or equal to the strain energy threshold.

9. A computer-readable storage medium, characterized in that, The storage medium stores a computer program that, when run on a computer, causes the computer to perform the method described in any one of claims 1-7.

10. A computer program product, characterized in that, When it is run on a computer, it performs the method described in any one of claims 1-7.

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