AA6061-T6铝合金点焊接头拉剪失效分析

Fracture Analysis of AA6061-T6 Aluminum Alloy Spot Welding Lap Shear Model

摘要: 以1.0 mm厚的AA6061-T6铝合金为例，建立其点焊接头的拉剪失效过程有限元模型，并对接头的不同区域分别赋予熔核区、热影响区和母材的材料属性。结果表明：接头发生纽扣断裂模式时，裂纹首先在熔核边缘产生，进而沿板厚方向扩展，直至焊点被拉脱；该仿真结果与实验结果相吻合，表明本文所建立的有限元模型具有较高的精度。基于有限元分析结果，基于不同的熔核直径下点焊接头的失效过程，建立了接头拉剪强度的预测公式。

Abstract: In this paper, a finite element model of AA6061-T6 aluminum alloy spot welding lap-shear joint is built by taking the 1.0mm stamped sheet. According to the different physical properties of the material in different regions of the joint, different material properties is applied for the nugget, heat-affected zone, and material zone. For button fracture failure mode, the result shows crack is produced at the edge of nugget firstly, and expanded along thickness direction until the button is pulled out. The numerical simulation results coincided well with the test results, it is a proof that the finite element model established in this paper has high accuracy. Based the result of finite element model, the prediction formula of lap-shear strength is given for pull-out fracture failure mode in different nugget size.