Material constitutive parameter optimizing method and device, electronic equipment and storage medium

Abstract

The invention discloses a material constitutive parameter optimization method and device, electronic equipment and a storage medium. The method comprises the steps that node force, torque and welding spot service life of a sample at a plurality of welding spots are obtained, and each welding spot comprises a plurality of welding spot tiny units; according to the node force and the moment of force of each welding spot, based on material constitutive parameters, calculating the structural stress of each welding spot micro unit for representing welding spot fatigue damage parameters; and the material constitutive parameters are adjusted to update the structural stress, and when the fitting effect of the structural stress of each welding spot tiny unit and the corresponding welding spot service life is optimal, the optimal material constitutive parameters are obtained. According to the method, optimization of material constitutive parameters is achieved, and meanwhile the precision of a welding spot fatigue curve represented by structural stress and the service life of a welding spot is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of materials, and in particular to a material constitutive parameter optimization method, device, electronic equipment and storage medium. Background Art

[0002] During the vehicle design process, it is necessary to conduct finite element analysis of the fatigue weld life of the vehicle welds. Through finite element analysis, welds with fatigue cracking risks can be quickly located before road tests, and targeted structural optimization can be performed in the early stages of design, thereby greatly shortening the development cycle and reducing development costs.

[0003] The accuracy of the finite element analysis results of fatigue solder joint life depends on the material constitutive model. The most commonly used constitutive model is the Rupp structural stress constitutive model based on solder joint force and moment. Due to the different manufacturing processes and levels of solder joints of each OEM, it is impossible to use a universal material curve to cover all solder joint material constitutive models. Therefore, different OEMs will establish solder joint fatigue material constitutive models according to their own manufacturing processes and levels, and calculate solder joint fatigue curves based on solder joint fatigue material constitutive models.

[0004] The existing weld fatigue material constitutive model needs to be calculated based on multiple material constitutive parameters. However, the existing technology only sets the material constitutive parameters through empirical values ​​and lacks a method for optimizing the material constitutive parameters, resulting in insufficient accuracy of the calculated weld fatigue curve. Summary of the invention

[0005] Based on this, it is necessary to provide a material constitutive parameter optimization method, device, electronic device and storage medium to address the technical problem that the existing technology lacks the ability to optimize material constitutive parameters.

[0006] The present invention provides a material constitutive parameter optimization method, comprising:

[0007] Obtaining the node force, moment and weld life of the sample at multiple weld points, each of the weld points includes multiple weld point micro units;

[0008] According to the node force and the moment of each weld point, based on the initial value of the material constitutive parameter, the structural stress of each weld point micro-unit for characterizing the fatigue damage parameter of the weld point is calculated;

[0009] The material constitutive parameters are adjusted to update the structural stress, and when the fitting effect between the structural stress of each solder joint micro-unit and the corresponding solder joint life is optimal, the optimal material constitutive parameters are obtained.

[0010] Further, the adjusting the material constitutive parameters to update the structural stress, and obtaining the optimal material constitutive parameters when the fitting effect between the structural stress of each solder joint micro-unit and the corresponding solder joint life is optimal, includes:

[0011] Fitting the structural stress of each solder joint micro-unit in each sample with the corresponding solder joint life to obtain a fitting curve;

[0012] The material constitutive parameters are adjusted to update the structural stress, the fitting curve is updated based on the updated structural stress, the fitting curve with the best fitting effect is used as the optimal fitting curve, and the material constitutive parameters corresponding to the structural stress that generates the optimal fitting curve are used as the optimal material constitutive parameters.

[0013] Furthermore, the fitting curve is obtained by fitting the structural stress of each solder joint micro-unit in each sample with the corresponding solder joint life, including:

[0014] The structural stress of each solder joint micro-unit and the corresponding solder joint life are taken as a scattered point, the abscissa of the scattered point is the solder joint life of the solder joint containing the solder joint micro-unit, and the ordinate of the scattered point is the structural stress of the solder joint micro-unit;

[0015] The scattered points are fitted to obtain a fitting curve.

[0016] Further, fitting the scattered points to obtain a fitting curve includes:

[0017] Based on S = a × Life b The scattered points are fitted to obtain a fitting curve, wherein S is the structural stress, Life is the solder joint life, a is the first fitting coefficient, and b is the second fitting coefficient.

[0018] Further, the adjusting the material constitutive parameters to update the structural stress, updating the fitting curve based on the updated structural stress, taking the fitting curve with the best fitting effect as the optimal fitting curve, and taking the material constitutive parameters corresponding to the structural stress for generating the optimal fitting curve as the optimal material constitutive parameters, includes:

[0019] Adjusting the material constitutive parameters, and recalculating the structural stresses of all the solder joint micro-units in all the specimens based on the adjusted material constitutive parameters, updating the scattered points based on the recalculated structural stresses, and recalculating the fitting curve based on the updated scattered points until the fitting effect of the fitting curve is optimal;

[0020] The fitting curve with the best fitting effect is taken as the optimal fitting curve, and the material constitutive parameters corresponding to the structural stress that generates the optimal fitting curve are taken as the optimal material constitutive parameters.

[0021] Further, the adjusting the material constitutive parameters, and recalculating the structural stresses of all the solder joint micro-units in all the samples based on the adjusted material constitutive parameters, updating the scattered points based on the recalculated structural stresses, and recalculating the fitting curve based on the updated scattered points until the fitting effect of the fitting curve is optimal, includes:

[0022] The material constitutive parameters are adjusted, and the structural stresses of all the micro-units of the weld points in all the samples are recalculated based on the adjusted material constitutive parameters, the scattered points are updated based on the recalculated structural stresses, and the fitting curve is recalculated based on the updated scattered points until the determination coefficient of the fitting curve with the scattered points is the largest, and the determination coefficient is R 2 coefficient.

[0023] Furthermore, the material constitutive parameters include:

[0024] A first load factor for load correction of the nodal force in the plane direction of the weld point;

[0025] The first diameter effect coefficient for correcting the nodal force in the plane direction of the weld point by the diameter effect;

[0026] The first thickness effect coefficient for performing thickness effect correction on the nodal force in the plane direction of the weld point;

[0027] A second load factor for load correction of the moment in the plane direction of the weld;

[0028] A second diameter effect coefficient for correcting the diameter effect of the moment in the plane direction of the weld point;

[0029] A second thickness effect coefficient for performing thickness effect correction on the moment in the plane direction of the weld point;

[0030] A third load factor for load correction of nodal forces in the direction perpendicular to the weld plane;

[0031] The third diameter effect coefficient for diameter effect correction of the node force in the direction perpendicular to the weld plane;

[0032] The third thickness effect coefficient for thickness effect correction of the nodal force in the direction perpendicular to the weld plane.

[0033] The present invention provides a material constitutive parameter optimization device, comprising:

[0034] A parameter acquisition module, used to obtain the node force, moment and weld life of the sample at multiple welds, each of which includes multiple weld micro units;

[0035] A structural stress calculation module, used to calculate the structural stress of each of the solder joint micro-units for characterizing the fatigue damage parameters of the solder joint according to the node force and the moment of each of the solder joints and based on the initial value of the material constitutive parameter;

[0036] The optimization module is used to adjust the material constitutive parameters to update the structural stress, and obtain the optimal material constitutive parameters when the fitting effect between the structural stress of each solder joint micro-unit and the corresponding solder joint life is optimal.

[0037] The present invention provides an electronic device, comprising:

[0038] at least one processor; and,

[0039] a memory communicatively connected to at least one of the processors; wherein,

[0040] The memory stores instructions that can be executed by at least one of the processors. The instructions are executed by at least one of the processors so that the at least one of the processors can execute the material constitutive parameter optimization method as described above.

[0041] The present invention provides a storage medium, wherein the storage medium stores computer instructions, and when a computer executes the computer instructions, it is used to execute all steps of the material constitutive parameter optimization method as described above.

[0042] The present invention builds a finite element model for fatigue test of the sample, calculates the structural stress of each micro-unit of the solder joint for characterizing the fatigue damage parameter of the solder joint according to the node force and the moment of each solder joint, and adjusts the material constitutive parameter to update the structural stress. When the fitting effect of the structural stress of each micro-unit of the solder joint and the corresponding solder joint life is optimal, the optimal material constitutive parameter is obtained. The present invention divides the solder joint into a plurality of micro-units of the solder joint, so as to obtain the accurate structural stress of different positions on the solder joint. At the same time, the material constitutive parameter is adjusted to update the structural stress, and the updated structural stress is fitted with the corresponding solder joint life. Therefore, when the optimal fitting effect is obtained, the optimal material constitutive parameter can be obtained, and the optimization of the material constitutive parameter is realized. At the same time, since the optimal material constitutive parameter is obtained when the fitting effect is optimal, the corresponding relationship between the structural stress calculated according to the optimal material constitutive parameter and the solder joint life is optimal, thereby improving the accuracy of the solder joint fatigue curve represented by the structural stress and the solder joint life. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a workflow diagram of a material constitutive parameter optimization method according to an embodiment of the present invention;

[0044] Figure 2 This is a workflow diagram of a material constitutive parameter optimization method according to another embodiment of the present invention;

[0045] Figure 3 The following is a flowchart of the material constitutive parameter optimization method of the best embodiment of the present invention;

[0046] Figure 4 A schematic diagram of writing the required parameters and calculation formulas into Excel for the best embodiment of the present invention;

[0047] Figure 5 A schematic diagram of calculating R2 using a formula in Excel for the best embodiment of the present invention;

[0048] Figure 6 A workflow diagram of a specific setting flow of the optimization process of the best embodiment of the present invention;

[0049] Figure 7 A schematic diagram of a material constitutive parameter optimization device according to an embodiment of the present invention;

[0050] Figure 8 The figure is a schematic diagram of the hardware structure of an electronic device of the present invention. DETAILED DESCRIPTION

[0051] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. The same components are represented by the same reference numerals. It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to directions in the accompanying drawings, and the words "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0052] like Figure 1 The figure shows a working flow chart of a material constitutive parameter optimization method according to an embodiment of the present invention, comprising:

[0053] Step S101, obtaining the node force, moment and solder joint life of the sample at multiple solder joints, each of the solder joints including multiple solder joint micro units;

[0054] Step S102, calculating the structural stress of each solder joint micro-unit for characterizing the solder joint fatigue damage parameter according to the node force and the moment of each solder joint and based on the initial value of the material constitutive parameter;

[0055] Step S103, adjusting the material constitutive parameters to update the structural stress, and obtaining the optimal material constitutive parameters when the fitting effect between the structural stress of each solder joint micro-unit and the corresponding solder joint life is optimal.

[0056] Specifically, the present invention can be applied to electronic devices with processing capabilities, such as computers.

[0057] First, step S101 is performed to obtain the node force, moment and weld life of the sample at multiple welds.

[0058] In some embodiments, obtaining the node force, moment and weld life of the sample at multiple welds includes: building a finite element model for fatigue testing of the sample, and obtaining the node force, moment and weld life of the sample at multiple welds from the finite element model.

[0059] Specifically, a finite element model is built based on the experiment, and the nodal force and moment of the weld during the experiment are extracted through the finite element model. The specimens in the experiment include shear (TS) / tension (CP) specimens. The two specimens will be divided into different numbers of groups and fatigue tests will be carried out under different loads. Taking Table 1 as an example, the CP / TS specimens are divided into five groups for fatigue tests, so it is necessary to build corresponding finite element models to extract the nodal force and moment of the weld under different loads. At the same time, the weld life of each weld is also obtained. Among them, the specimen is preferably a plate with welded welds, such as a steel plate with welded welds.

[0060] Table 1 Experimental table

[0061]

[0062] Then, step S102 is performed to calculate the structural stress of each micro-unit of the weld point for characterizing the fatigue damage parameter of the weld point according to the node force and the moment of each weld point and based on the initial value of the material constitutive parameter.

[0063] Among them, each solder joint can be divided into multiple tiny units.

[0064] In some embodiments, for each solder joint, a circle is established with the center of the solder joint as the center, and the circle is evenly divided into a plurality of sectors, each sector being a micro unit.

[0065] Then, the structural stress of each micro-unit is calculated. The structural stress is calculated based on the material constitutive parameters using the existing structural stress calculation method.

[0066] In some embodiments, the calculating of the structural stress of each micro-unit of the weld point for characterizing the fatigue damage parameter of the weld point based on the node force and the moment of each weld point and the initial value of the material constitutive parameter includes:

[0067] According to the node force, moment, diameter and geometric parameters of the weld, based on the initial values ​​of the material constitutive parameters, the structural stress of each weld micro-unit for characterizing the fatigue damage parameters of the weld is calculated.

[0068] Preferably, the sample is a plate, and the geometric parameters of the sample are the geometric parameters of the plate.

[0069] More preferably, the plate geometric parameter is the minimum plate thickness (referred to as minimum plate thickness).

[0070] Finally, step S103 is executed to adjust the material constitutive parameters to update the structural stress, and when the fitting effect between the structural stress of each solder joint micro-unit and the corresponding solder joint life is optimal, the optimal material constitutive parameters are obtained.

[0071] Specifically, the structural stress of each solder joint micro-unit is fitted with the corresponding solder joint life, and after fitting, the material constitutive parameters are adjusted to obtain a new structural stress, and the new structural stress is fitted with the solder joint life again to obtain different fitting results, and by comparing the fitting results, the material constitutive parameters when the best fitting results are obtained are selected as the optimal material constitutive parameters. The obtained optimal material constitutive parameters can be used to establish a material constitutive model using the existing modeling method, and based on the material constitutive model, the existing fatigue curve calculation method is used to obtain the solder joint fatigue curve.

[0072] like Figure 3 The flowchart of the material constitutive parameter optimization method of the best embodiment of the present invention is shown, including:

[0073] Step S301, performing fatigue test based on the strength of TS / CP specimens;

[0074] Step S302, establishing a finite element model;

[0075] Step S303, optimizing material constitutive parameters;

[0076] Step S304: characterizing the material constitutive model with the optimal material constitutive parameters.

[0077] The present invention builds a finite element model for fatigue test of the sample, calculates the structural stress of each micro-unit of the solder joint for characterizing the fatigue damage parameter of the solder joint according to the node force and the moment of each solder joint, and adjusts the material constitutive parameter to update the structural stress. When the fitting effect of the structural stress of each micro-unit of the solder joint and the corresponding solder joint life is optimal, the optimal material constitutive parameter is obtained. The present invention divides the solder joint into a plurality of micro-units of the solder joint, so as to obtain the accurate structural stress of different positions on the solder joint. At the same time, the material constitutive parameter is adjusted to update the structural stress, and the updated structural stress is fitted with the corresponding solder joint life. Therefore, when the optimal fitting effect is obtained, the optimal material constitutive parameter can be obtained, and the optimization of the material constitutive parameter is realized. At the same time, since the optimal material constitutive parameter is obtained when the fitting effect is optimal, the corresponding relationship between the structural stress calculated according to the optimal material constitutive parameter and the solder joint life is optimal, thereby improving the accuracy of the solder joint fatigue curve represented by the structural stress and the solder joint life.

[0078] like Figure 2 The figure shows a working flow chart of a material constitutive parameter optimization method in another embodiment of the present invention, comprising:

[0079] Step S201, obtaining the node force, moment and solder joint life of the sample at multiple solder joints, each of the solder joints including multiple solder joint micro units.

[0080] Step S202, calculating the structural stress of each micro-unit of the weld point for characterizing the fatigue damage parameter of the weld point according to the node force and the moment of each weld point and based on the initial value of the material constitutive parameter.

[0081] In one embodiment, the material constitutive parameters include:

[0082] A first load factor for load correction of the nodal force in the plane direction of the weld point;

[0083] The first diameter effect coefficient for correcting the nodal force in the plane direction of the weld point by the diameter effect;

[0084] The first thickness effect coefficient for performing thickness effect correction on the nodal force in the plane direction of the weld point;

[0085] A second load factor for load correction of the moment in the plane direction of the weld;

[0086] A second diameter effect coefficient for correcting the diameter effect of the moment in the plane direction of the weld point;

[0087] A second thickness effect coefficient for performing thickness effect correction on the moment in the plane direction of the weld point;

[0088] A third load factor for load correction of nodal forces in the direction perpendicular to the weld plane;

[0089] The third diameter effect coefficient for diameter effect correction of the node force in the direction perpendicular to the weld plane;

[0090] The third thickness effect coefficient for thickness effect correction of the nodal force in the direction perpendicular to the weld plane.

[0091] Step S203, fitting the structural stress of each solder joint micro-unit in each sample and the corresponding solder joint life to obtain a fitting curve.

[0092] In one embodiment, the fitting curve obtained by fitting the structural stress of each solder joint micro-unit in each sample with the corresponding solder joint life includes:

[0093] The structural stress of each solder joint micro-unit and the corresponding solder joint life are taken as a scattered point, the abscissa of the scattered point is the solder joint life of the solder joint containing the solder joint micro-unit, and the ordinate of the scattered point is the structural stress of the solder joint micro-unit;

[0094] The scattered points are fitted to obtain a fitting curve.

[0095] In one embodiment, fitting the scattered points to obtain a fitting curve includes:

[0096] Based on S = a × Life b The scattered points are fitted to obtain a fitting curve, wherein S is the structural stress, Life is the solder joint life, a is the first fitting coefficient, and b is the second fitting coefficient.

[0097] Step S204, adjusting the material constitutive parameters to update the structural stress, updating the fitting curve based on the updated structural stress, taking the fitting curve with the best fitting effect as the optimal fitting curve, and taking the material constitutive parameters corresponding to the structural stress that generates the optimal fitting curve as the optimal material constitutive parameters.

[0098] In one embodiment, the adjusting the material constitutive parameters to update the structural stress, updating the fitting curve based on the updated structural stress, taking the fitting curve with the best fitting effect as the optimal fitting curve, and taking the material constitutive parameters corresponding to the structural stress that generates the optimal fitting curve as the optimal material constitutive parameters, includes:

[0099] Adjusting the material constitutive parameters, and recalculating the structural stresses of all the solder joint micro-units in all the specimens based on the adjusted material constitutive parameters, updating the scattered points based on the recalculated structural stresses, and recalculating the fitting curve based on the updated scattered points until the fitting effect of the fitting curve is optimal;

[0100] The fitting curve with the best fitting effect is taken as the optimal fitting curve, and the material constitutive parameters corresponding to the structural stress that generates the optimal fitting curve are taken as the optimal material constitutive parameters.

[0101] In one embodiment, the adjusting the material constitutive parameters, and recalculating the structural stresses of all the solder joint micro-units in all the samples based on the adjusted material constitutive parameters, updating the scattered points based on the recalculated structural stresses, and recalculating the fitting curve based on the updated scattered points until the fitting effect of the fitting curve is optimal, includes:

[0102] The material constitutive parameters are adjusted, and the structural stresses of all the micro-units of the weld points in all the samples are recalculated based on the adjusted material constitutive parameters, the scattered points are updated based on the recalculated structural stresses, and the fitting curve is recalculated based on the updated scattered points until the determination coefficient of the fitting curve with the scattered points is the largest, and the determination coefficient is R 2 coefficient.

[0103] Specifically, firstly, step S201 is executed to build a finite element model for fatigue testing of a sample, and obtain the node force, moment and weld life of the sample at multiple welds from the finite element model.

[0104] Then, step S202 is performed to calculate the structural stress of each micro-unit of the weld point for characterizing the fatigue damage parameter of the weld point according to the node force and the moment of each weld point and based on the initial value of the material constitutive parameter.

[0105] In one embodiment, the material constitutive parameters include:

[0106] A first load factor for load correction of the nodal force in the plane direction of the weld point;

[0107] The first diameter effect coefficient for correcting the nodal force in the plane direction of the weld point by the diameter effect;

[0108] The first thickness effect coefficient for performing thickness effect correction on the nodal force in the plane direction of the weld point;

[0109] A second load factor for load correction of the moment in the plane direction of the weld;

[0110] A second diameter effect coefficient for correcting the diameter effect of the moment in the plane direction of the weld point;

[0111] A second thickness effect coefficient for performing thickness effect correction on the moment in the plane direction of the weld point;

[0112] A third load factor for load correction of nodal forces in the direction perpendicular to the weld plane;

[0113] The third diameter effect coefficient for diameter effect correction of the node force in the direction perpendicular to the weld plane;

[0114] The third thickness effect coefficient for thickness effect correction of the nodal force in the direction perpendicular to the weld plane.

[0115] Specifically, there are 9 material constitutive parameters.

[0116] In some embodiments, there are 17 parameters used to calculate structural stress, as shown in Table 2.

[0117] Table 2 Structural stress calculation parameters

[0118]

[0119]

[0120] Next, based on the above 17 parameters, the structural stress used to characterize the fatigue damage parameters of the solder joint can be calculated through the following expression.

[0121] For the i-th specimen, the equivalent structural stress of one of the welds is:

[0122] σ sheet,i,θ =-σ max (FXi)cosθ-σ max (FYi)sinθ+σ(FZi)+σ max (MXi)sinθ-σ max (FYi)cosθ(1)

[0123] in,

[0124]

[0125]

[0126]

[0127]

[0128]

[0129] In the formula, σ sheet,i,θis the structural stress of the weld micro-unit with an angle of θ in the weld of the ith specimen, θ is the angle of the weld micro-unit, FXi is the node force in the x-direction of the weld local coordinate system of the ith specimen, FYi is the node force in the y-direction of the weld local coordinate system of the ith specimen, FZi is the node force in the z-direction of the weld local coordinate system of the ith specimen, MXi is the moment in the x-direction of the weld local coordinate system of the ith specimen, MYi is the moment in the y-direction of the weld local coordinate system of the ith specimen, MZi is the moment in the z-direction of the weld local coordinate system of the ith specimen, si is the thickness of the ith specimen, preferably the minimum thickness, d is the weld diameter, π is a mathematical constant, SFFXY is the first load coefficient for load correction of the node force in the plane direction of the weld, and DEFXY is the moment in the plane direction of the weld. The first diameter effect coefficient for correcting the diameter effect of the node force in the direction of the weld plane, TEFXY is the first thickness effect coefficient for correcting the thickness effect of the node force in the direction of the weld plane, SFMXY is the second load coefficient for correcting the load of the moment in the direction of the weld plane, DEMXY is the second diameter effect coefficient for correcting the diameter effect of the moment in the direction of the weld plane, TEMXY is the second thickness effect coefficient for correcting the thickness effect of the moment in the direction of the weld plane, SFFZ is the third load coefficient for correcting the load of the node force in the direction perpendicular to the weld plane, DEFZ is the third diameter effect coefficient for correcting the diameter effect of the node force in the direction perpendicular to the weld plane, and TEFZ is the third thickness effect coefficient for correcting the thickness effect of the node force in the direction perpendicular to the weld plane.

[0130] Preferably, the sample is a plate.

[0131] At the beginning, according to the node force and the moment of each weld point, based on the initial value of the material constitutive parameter, the structural stress of each weld point micro-unit for characterizing the weld point fatigue damage parameter is calculated. Table 3 is an example of the initial value of the material constitutive parameter.

[0132]

[0133] This embodiment sets material constitutive parameters in multiple directions according to the load coefficient, diameter effect and thickness effect to obtain accurate structural stress.

[0134] Then, step S203 is performed to fit the structural stress of each solder joint micro-unit in each sample with the corresponding solder joint life to obtain a fitting curve.

[0135] Specifically, each sample has multiple solder joints, each solder joint is divided into multiple solder joint micro-units, and the structural stress of each solder joint micro-unit included in each solder joint of each sample is calculated based on the aforementioned formulas (1) to (6). At the same time, each solder joint micro-unit is associated with the solder joint life of the solder joint containing the solder joint micro-unit, and a fitting curve is obtained by fitting.

[0136] In one embodiment, the fitting curve obtained by fitting the structural stress of each solder joint micro-unit in each sample with the corresponding solder joint life includes:

[0137] The structural stress of each solder joint micro-unit and the corresponding solder joint life are taken as a scattered point, the abscissa of the scattered point is the solder joint life of the solder joint containing the solder joint micro-unit, and the ordinate of the scattered point is the structural stress of the solder joint micro-unit;

[0138] The scattered points are fitted to obtain a fitting curve.

[0139] Specifically, a two-dimensional coordinate system is established, with the solder joint life as the horizontal coordinate and the structural stress as the vertical coordinate. The tiny units of the solder joints are converted into scattered points, and then the scattered points are fitted to obtain the fitting curve of the structural stress and the solder joint life.

[0140] This embodiment determines the scattered points based on the structural stress of the solder joint micro-unit and the solder joint life, so as to facilitate fitting to obtain the fitting curve.

[0141] In one embodiment, fitting the scattered points to obtain a fitting curve includes:

[0142] Based on S = a × Life b The scattered points are fitted to obtain a fitting curve, wherein S is the structural stress, Life is the solder joint life, a is the first fitting coefficient, and b is the second fitting coefficient.

[0143] Specifically, this embodiment adopts S = a × Life b As the fitting function, the structural stress of multiple scattered points is substituted into S, and the solder joint life is substituted into Life, and the first fitting coefficient a and the second fitting coefficient b are obtained through fitting calculation.

[0144] This embodiment provides a fitting function to accurately fit the structural stress and the solder joint life.

[0145] Finally, execute step S204, adjust the material constitutive parameters to update the structural stress, update the fitting curve based on the updated structural stress, use the fitting curve with the best fitting effect as the optimal fitting curve, and use the material constitutive parameters corresponding to the structural stress that generates the optimal fitting curve as the optimal material constitutive parameters.

[0146] Specifically, after obtaining the fitting curve, the fitting effect of the fitting curve is judged to determine whether the calculation of the structural stress is appropriate. If it is not appropriate, the material constitutive parameters are adjusted and the structural stress is calculated again until the fitting effect is optimal and the optimal material constitutive parameters are obtained.

[0147] In one embodiment, the adjusting the material constitutive parameters to update the structural stress, updating the fitting curve based on the updated structural stress, taking the fitting curve with the best fitting effect as the optimal fitting curve, and taking the material constitutive parameters corresponding to the structural stress that generates the optimal fitting curve as the optimal material constitutive parameters, includes:

[0148] Adjusting the material constitutive parameters, and recalculating the structural stresses of all the solder joint micro-units in all the specimens based on the adjusted material constitutive parameters, updating the scattered points based on the recalculated structural stresses, and recalculating the fitting curve based on the updated scattered points until the fitting effect of the fitting curve is optimal;

[0149] The fitting curve with the best fitting effect is taken as the optimal fitting curve, and the material constitutive parameters corresponding to the structural stress that generates the optimal fitting curve are taken as the optimal material constitutive parameters.

[0150] Specifically, the process of optimizing the material constitutive parameters is to gradually adjust the material constitutive parameters. After each adjustment of the material constitutive parameters, the structural stresses of all the weld micro-units in all the samples are recalculated using the above-mentioned formulas (1) to (6) based on the adjusted material constitutive parameters, and then step S203 is re-executed to calculate the fitting curve again until the fitting effect of the fitting curve is optimal.

[0151] This embodiment provides specific steps for optimizing material constitutive parameters, and by comparing the fitting effects of fitting curves, the optimal material constitutive parameters are quickly and accurately obtained.

[0152] In one embodiment, the adjusting the material constitutive parameters, and recalculating the structural stresses of all the solder joint micro-units in all the samples based on the adjusted material constitutive parameters, updating the scattered points based on the recalculated structural stresses, and recalculating the fitting curve based on the updated scattered points until the fitting effect of the fitting curve is optimal, includes:

[0153] The material constitutive parameters are adjusted, and the structural stresses of all the micro-units of the weld points in all the samples are recalculated based on the adjusted material constitutive parameters, the scattered points are updated based on the recalculated structural stresses, and the fitting curve is recalculated based on the updated scattered points until the determination coefficient of the fitting curve with the scattered points is the largest, and the determination coefficient is R 2 coefficient.

[0154] Specifically, this embodiment determines the fitting effect of the fitting curve by the determination coefficient. 2 Coefficient. R 2 The coefficient is used to judge the fitting effect of the fitting curve and the scattered points, and the determination coefficient R 2 The larger it is, the better the fitting effect is.

[0155] This embodiment uses the determination coefficient to evaluate the fitting effect of the fitting curve, so as to quantitatively measure the accuracy of the material constitutive parameters obtained by optimization.

[0156] In some embodiments, joint parameter optimization can be performed through Hyperworks and Excel, wherein Hyperworks is a modeling and simulation software, and Excel is a spreadsheet software of Microsoft Corporation.

[0157] Specifically, the required parameters and calculation formulas are written into Excel, and then the formulas are used in Excel to calculate the structural stress of different specimens, such as Figure 4 shown.

[0158] At the same time, Figure 4 The Excel file shown in R 2 Use the formula to calculate it as the target value of the entire optimization process, and get Figure 5 As shown in Excel.

[0159] Finally, Hyperworks was used as a parameter optimization solver, with 9 material constitutive parameters as input and R 2 The parameter optimization is carried out with the maximum as the goal, and finally a set of fatigue material constitutive parameters can be obtained so that R 2 The specific setting process of the optimization process is as follows Figure 6 As shown, including:

[0160] Step S601, importing Excel into Hyperworks;

[0161] Step S602: Select the material constitutive model as input in Hyperworks and select R 2 is the output;

[0162] Step S603: Set the response optimization range in Hyperworks and set the output target to R 2 maximum;

[0163] Step S604, selecting the optimization algorithm as the improved particle optimization algorithm in Hyperworks;

[0164] Step S605: Hyperworks starts iterative optimization.

[0165] This embodiment calculates the structural stress of the tiny unit of the solder joint, establishes a fitting curve of the structural stress and the solder joint life, and optimizes the material constitutive parameters by comparing the fitting effects. This can greatly shorten the material constitutive parameter optimization time, thereby improving the accuracy of the solder joint fatigue curve.

[0166] Based on the same inventive concept, Figure 7 The figure shows a schematic diagram of a material constitutive parameter optimization device according to an embodiment of the present invention, comprising:

[0167] The parameter acquisition module 701 is used to build a finite element model for fatigue testing of a sample, and obtain the node force, moment and weld life of the sample at multiple welds from the finite element model, each weld including multiple weld micro units;

[0168] A structural stress calculation module 702 is used to calculate the structural stress of each of the micro-units of the solder joint for characterizing the fatigue damage parameter of the solder joint according to the node force and the moment of each of the solder joints and based on the initial value of the material constitutive parameter;

[0169] The optimization module 703 is used to adjust the material constitutive parameters to update the structural stress, and obtain the optimal material constitutive parameters when the fitting effect between the structural stress of each solder joint micro unit and the corresponding solder joint life is optimal.

[0170] The present invention builds a finite element model for fatigue test of the sample, calculates the structural stress of each micro-unit of the solder joint for characterizing the fatigue damage parameter of the solder joint according to the node force and the moment of each solder joint, and adjusts the material constitutive parameter to update the structural stress. When the fitting effect of the structural stress of each micro-unit of the solder joint and the corresponding solder joint life is optimal, the optimal material constitutive parameter is obtained. The present invention divides the solder joint into a plurality of micro-units of the solder joint, so as to obtain the accurate structural stress of different positions on the solder joint. At the same time, the material constitutive parameter is adjusted to update the structural stress, and the updated structural stress is fitted with the corresponding solder joint life. Therefore, when the optimal fitting effect is obtained, the optimal material constitutive parameter can be obtained, and the optimization of the material constitutive parameter is realized. At the same time, since the optimal material constitutive parameter is obtained when the fitting effect is optimal, the corresponding relationship between the structural stress calculated according to the optimal material constitutive parameter and the solder joint life is optimal, thereby improving the accuracy of the solder joint fatigue curve represented by the structural stress and the solder joint life.

[0171] In one embodiment, the adjusting the material constitutive parameters to update the structural stress, and obtaining the optimal material constitutive parameters when the fitting effect between the structural stress of each solder joint micro-unit and the corresponding solder joint life is optimal, includes:

[0172] Fitting the structural stress of each solder joint micro-unit in each sample with the corresponding solder joint life to obtain a fitting curve;

[0173] The material constitutive parameters are adjusted to update the structural stress, the fitting curve is updated based on the updated structural stress, the fitting curve with the best fitting effect is used as the optimal fitting curve, and the material constitutive parameters corresponding to the structural stress that generates the optimal fitting curve are used as the optimal material constitutive parameters.

[0174] In one embodiment, the fitting curve obtained by fitting the structural stress of each solder joint micro-unit in each sample with the corresponding solder joint life includes:

[0175] The structural stress of each solder joint micro-unit and the corresponding solder joint life are taken as a scattered point, the abscissa of the scattered point is the solder joint life of the solder joint containing the solder joint micro-unit, and the ordinate of the scattered point is the structural stress of the solder joint micro-unit;

[0176] The scattered points are fitted to obtain a fitting curve.

[0177] In one embodiment, fitting the scattered points to obtain a fitting curve includes:

[0178] Based on S = a × Life b The scattered points are fitted to obtain a fitting curve, wherein S is the structural stress, Life is the solder joint life, a is the first fitting coefficient, and b is the second fitting coefficient.

[0179] In one embodiment, the adjusting the material constitutive parameters to update the structural stress, updating the fitting curve based on the updated structural stress, taking the fitting curve with the best fitting effect as the optimal fitting curve, and taking the material constitutive parameters corresponding to the structural stress that generates the optimal fitting curve as the optimal material constitutive parameters, includes:

[0180] Adjusting the material constitutive parameters, and recalculating the structural stresses of all the solder joint micro-units in all the specimens based on the adjusted material constitutive parameters, updating the scattered points based on the recalculated structural stresses, and recalculating the fitting curve based on the updated scattered points until the fitting effect of the fitting curve is optimal;

[0181] The fitting curve with the best fitting effect is taken as the optimal fitting curve, and the material constitutive parameters corresponding to the structural stress that generates the optimal fitting curve are taken as the optimal material constitutive parameters.

[0182] In one embodiment, the adjusting the material constitutive parameters, and recalculating the structural stresses of all the solder joint micro-units in all the samples based on the adjusted material constitutive parameters, updating the scattered points based on the recalculated structural stresses, and recalculating the fitting curve based on the updated scattered points until the fitting effect of the fitting curve is optimal, includes:

[0183] The material constitutive parameters are adjusted, and the structural stresses of all the micro-units of the weld points in all the samples are recalculated based on the adjusted material constitutive parameters, the scattered points are updated based on the recalculated structural stresses, and the fitting curve is recalculated based on the updated scattered points until the determination coefficient of the fitting curve with the scattered points is the largest, and the determination coefficient is R 2 coefficient.

[0184] In one embodiment, the material constitutive parameters include:

[0185] A first load factor for load correction of the nodal force in the plane direction of the weld point;

[0186] The first diameter effect coefficient for correcting the nodal force in the plane direction of the weld point by the diameter effect;

[0187] The first thickness effect coefficient for performing thickness effect correction on the nodal force in the plane direction of the weld point;

[0188] A second load factor for load correction of the moment in the plane direction of the weld;

[0189] A second diameter effect coefficient for correcting the diameter effect of the moment in the plane direction of the weld point;

[0190] A second thickness effect coefficient for performing thickness effect correction on the moment in the plane direction of the weld point;

[0191] A third load factor for load correction of nodal forces in the direction perpendicular to the weld plane;

[0192] The third diameter effect coefficient for diameter effect correction of the node force in the direction perpendicular to the weld plane;

[0193] The third thickness effect coefficient for thickness effect correction of the nodal force in the direction perpendicular to the weld plane.

[0194] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0195] like Figure 8 The figure shows a hardware structure diagram of an electronic device of the present invention, including:

[0196] at least one processor 801; and,

[0197] A memory 802 is communicatively connected to at least one of the processors 801; wherein,

[0198] The memory 802 stores instructions that can be executed by at least one of the processors. The instructions are executed by at least one of the processors so that the at least one processor can execute the material constitutive parameter optimization method as described above.

[0199] Figure 8 A processor 801 is taken as an example.

[0200] The electronic device may further include: an input device 803 and a display device 804 .

[0201] The processor 801, the memory 802, the input device 803 and the display device 804 may be connected via a bus or other means, and the figure takes the connection via a bus as an example.

[0202] The memory 802 is a non-volatile computer-readable storage medium that can be used to store non-volatile software programs, non-volatile computer executable programs and modules, such as program instructions / modules corresponding to the material constitutive parameter optimization method in the embodiment of the present application, for example, Figure 1 , Figure 2The processor 801 executes various functional applications and data processing by running the non-volatile software programs, instructions and modules stored in the memory 802, that is, the material constitutive parameter optimization method in the above embodiment is implemented.

[0203] The memory 802 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required by at least one function; the data storage area may store data created according to the use of the material constitutive parameter optimization method, etc. In addition, the memory 802 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 802 may optionally include a memory remotely arranged relative to the processor 801, and these remote memories may be connected to a device for executing the material constitutive parameter optimization method via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0204] The input device 803 can receive user clicks and generate signal inputs related to user settings and function control of the material constitutive parameter optimization method. The display device 804 can include display devices such as a display screen.

[0205] The one or more modules are stored in the memory 802 , and when executed by the one or more processors 801 , the material constitutive parameter optimization method in any of the above method embodiments is executed.

[0206] The present invention builds a finite element model for fatigue test of the sample, calculates the structural stress of each micro-unit of the solder joint for characterizing the fatigue damage parameter of the solder joint according to the node force and the moment of each solder joint, and adjusts the material constitutive parameter to update the structural stress. When the fitting effect of the structural stress of each micro-unit of the solder joint and the corresponding solder joint life is optimal, the optimal material constitutive parameter is obtained. The present invention divides the solder joint into a plurality of micro-units of the solder joint, so as to obtain the accurate structural stress of different positions on the solder joint. At the same time, the material constitutive parameter is adjusted to update the structural stress, and the updated structural stress is fitted with the corresponding solder joint life. Therefore, when the optimal fitting effect is obtained, the optimal material constitutive parameter can be obtained, and the optimization of the material constitutive parameter is realized. At the same time, since the optimal material constitutive parameter is obtained when the fitting effect is optimal, the corresponding relationship between the structural stress calculated according to the optimal material constitutive parameter and the solder joint life is optimal, thereby improving the accuracy of the solder joint fatigue curve represented by the structural stress and the solder joint life.

[0207] An embodiment of the present invention provides a storage medium, wherein the storage medium stores computer instructions. When a computer executes the computer instructions, the storage medium is used to execute all steps of the material constitutive parameter optimization method as described above.

[0208] In the context of the present disclosure, a storage medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or apparatus. The storage medium may be a machine-readable signal medium or a machine-readable storage medium. Alternatively, the storage medium may be a non-temporary computer-readable storage medium, for example, a non-temporary computer-readable storage medium may be a ROM, a random access memory (Random Access Memory, RAM), a compact disc read-only memory (Compact Disc ROM, CD-ROM), a magnetic tape, a floppy disk, and an optical data storage device, etc.

[0209] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A material constitutive parameter optimization method, characterized in that: include: Obtaining the node force, moment and weld life of the sample at multiple weld points, each of the weld points includes multiple weld point micro units; According to the node force and the moment of each weld point, based on the material constitutive parameters, the structural stress of each weld point micro-unit for characterizing the fatigue damage parameter of the weld point is calculated; The material constitutive parameters are adjusted to update the structural stress, and when the fitting effect between the structural stress of each solder joint micro-unit and the corresponding solder joint life is optimal, the optimal material constitutive parameters are obtained.

2. The material constitutive parameter optimization method according to claim 1, characterized in that: The adjusting the material constitutive parameters to update the structural stress, and obtaining the optimal material constitutive parameters when the fitting effect between the structural stress of each solder joint micro-unit and the corresponding solder joint life is optimal, comprises: Fitting the structural stress of each solder joint micro-unit in each sample with the corresponding solder joint life to obtain a fitting curve; The material constitutive parameters are adjusted to update the structural stress, the fitting curve is updated based on the updated structural stress, the fitting curve with the best fitting effect is used as the optimal fitting curve, and the material constitutive parameters corresponding to the structural stress that generates the optimal fitting curve are used as the optimal material constitutive parameters.

3. The material constitutive parameter optimization method according to claim 2, characterized in that: The fitting curve is obtained by fitting the structural stress of each solder joint micro-unit in each sample with the corresponding solder joint life, including: The structural stress of each solder joint micro-unit and the corresponding solder joint life are taken as a scattered point, the abscissa of the scattered point is the solder joint life of the solder joint containing the solder joint micro-unit, and the ordinate of the scattered point is the structural stress of the solder joint micro-unit; The scattered points are fitted to obtain a fitting curve.

4. The material constitutive parameter optimization method according to claim 3, characterized in that: The step of fitting the scattered points to obtain a fitting curve comprises: Based on S = a × Life b The scattered points are fitted to obtain a fitting curve, wherein S is the structural stress, Life is the solder joint life, a is the first fitting coefficient, and b is the second fitting coefficient.

5. The material constitutive parameter optimization method according to claim 3, characterized in that: The step of adjusting the material constitutive parameters to update the structural stress, updating the fitting curve based on the updated structural stress, taking the fitting curve with the best fitting effect as the optimal fitting curve, and taking the material constitutive parameters corresponding to the structural stress for generating the optimal fitting curve as the optimal material constitutive parameters includes: Adjusting the material constitutive parameters, and recalculating the structural stresses of all the solder joint micro-units in all the specimens based on the adjusted material constitutive parameters, updating the scattered points based on the recalculated structural stresses, and recalculating the fitting curve based on the updated scattered points until the fitting effect of the fitting curve is optimal; The fitting curve with the best fitting effect is taken as the optimal fitting curve, and the material constitutive parameters corresponding to the structural stress that generates the optimal fitting curve are taken as the optimal material constitutive parameters.

6. The material constitutive parameter optimization method according to claim 5, characterized in that: The adjusting of the material constitutive parameters, and recalculating the structural stresses of all the solder joint micro-units in all the specimens based on the adjusted material constitutive parameters, updating the scattered points based on the recalculated structural stresses, and recalculating the fitting curve based on the updated scattered points until the fitting effect of the fitting curve is optimal, includes: The material constitutive parameters are adjusted, and the structural stresses of all the micro-units of the weld points in all the samples are recalculated based on the adjusted material constitutive parameters, the scattered points are updated based on the recalculated structural stresses, and the fitting curve is recalculated based on the updated scattered points until the determination coefficient of the fitting curve with the scattered points is the largest, and the determination coefficient is R 2 coefficient.

7. The material constitutive parameter optimization method according to any one of claims 1 to 6, characterized in that: The material constitutive parameters include: A first load factor for load correction of the nodal force in the plane direction of the weld point; The first diameter effect coefficient for correcting the nodal force in the plane direction of the weld point by the diameter effect; The first thickness effect coefficient for performing thickness effect correction on the nodal force in the plane direction of the weld point; A second load factor for load correction of the moment in the plane direction of the weld; A second diameter effect coefficient for correcting the diameter effect of the moment in the plane direction of the weld point; A second thickness effect coefficient for performing thickness effect correction on the moment in the plane direction of the weld point; A third load factor for load correction of nodal forces in the direction perpendicular to the weld plane; The third diameter effect coefficient for diameter effect correction of the node force in the direction perpendicular to the weld plane; The third thickness effect coefficient for thickness effect correction of the nodal force in the direction perpendicular to the weld plane.

8. A material constitutive parameter optimization device, characterized in that: include: A parameter acquisition module, used to obtain the node force, moment and weld life of the sample at multiple welds, each of which includes multiple weld micro units; A structural stress calculation module, used to calculate the structural stress of each of the micro-units of the solder joint for characterizing the fatigue damage parameters of the solder joint according to the node force and the moment of each of the solder joints and based on the initial value of the material constitutive parameter; The optimization module is used to adjust the material constitutive parameters to update the structural stress, and obtain the optimal material constitutive parameters when the fitting effect between the structural stress of each solder joint micro-unit and the corresponding solder joint life is optimal.

9. An electronic device, characterized in that: include: at least one processor; as well as, a memory communicatively connected to at least one of the processors; wherein, The memory stores instructions that can be executed by at least one of the processors, and the instructions are executed by at least one of the processors to enable at least one of the processors to execute the material constitutive parameter optimization method according to any one of claims 1 to 7.

10. A storage medium, characterized in that: The storage medium stores computer instructions, and when a computer executes the computer instructions, it is used to execute all steps of the material constitutive parameter optimization method as described in any one of claims 1 to 7.

Images