Simulation system for spot welding invalid number value

Abstract

The invention relates to a spot-welding connection failure value simulation system in the car bodywork manufacturing engineering field. In the invention, a circle-stress failure criterion generating module obtains nugget circle stress distribution form according to the failure mode of the spot-welding connection in a strike process to generate the circle stress failure criterion; a failure extremevalue stress and an index-parameter obtaining module obtain welding-spot critical failure stress extreme values and dimensionless stress sub-item index initial values under the condition of the peakvalues of four exterior loads; four types of sample value models which are pulling-cutting, pulling-extending, pulling-bending and pulling-twisting are established in a welding-spot connection value simulation module; an explicit dynamics analysis module couples circle stress failure criteria and obtains the continuous distributed inner stress of a welding-spot unit model and an extreme value stress borne by the welding-spot unit during failure time by simulation; a welding-spot failure material databank module stores the critical failure stress extreme values and the dimensionless stress sub-item index initial values of each stress component. The system not only can enhance the impact simulation precision without impact on the calculation efficiency, but also can reduce the design and exploitation cost.

Description

technical field [0001] The invention relates to a computer-aided system in the technical field of automobile engineering, in particular to a numerical simulation system for spot welding joint failure. Background technique [0002] Resistance spot welding is one of the basic assembly and connection methods in the modern automobile industry. The body structure is mainly composed of stamped sheets connected by solder joints. A typical body structure contains about 4000-7000 solder joints. The diameter of the weld nugget and the distance between the solder joints are It is determined by the thickness of the thin plate to be connected, usually the diameter of the weld nugget is between 3-7mm, and the average value is generally 6mm. In the research on the crash characteristics of automobiles, it is found that the failure of the connection method has a great influence on the test evaluation parameters, and the failure of the solder joints will affect the collision energy absorption...

AI Technical Summary

Problems solved by technology

The simulation process is mainly based on the force failure criterion of particle mechanics, and reasonable simulation results can be obtained for solder joint damage under static and quasi-static conditions, but for the simulation of solder joint failure during impact, because this type of failure criterion does not consider The real geometric form and material properties of the solder joints have certain defects. During the variable-rate vehicle impact simulation process, the strengthening effect of the strain rate effect on the ultimate failure load of the solder joints cannot be considered, so the failure criticality of the solder joints cannot be flexibly judged during the simulation process. value, which will bring a large degree of calculation error in the vehicle-level analysis

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