搅拌摩擦焊的三维有限元摩擦模型数值模拟研究

Study on Numerical Simulation on Friction Model of Three-dimensional Finite Element in Friction Stir Welding

搅拌摩擦焊(FSW)的三维有限元的摩擦模拟需要透彻地了解其材料和界面行为,其模型建立困难,同时很难认识其现象本质。由于材料流动的高度耦合性和极端条件,单纯的摩擦模型不能描述FSW的过程,需要对其有限元模型进行简化处理。对6061铝合金进行FSW试验,采用Forge有限元软件对FSW进行了分析。结果表明:焊接过程中的力和温度对摩擦系数具有高度敏感性,利用ALE算法可以计算出接触和摩擦表面的大小,Norton摩擦模型得到的力值与实验结果吻合良好,采用Coulomb模型进行校准得到摩擦系数μ=0.3。

Three-dimensional finite element simulation of friction stir welding（FSW） required a thorough understanding of the material friction and interface behavior, the establishment of the model was difficult, and the essence was difficult to identify. According to the extreme encountered conditions and the highly coupled nature of the material flow, the simple tribological tests were not representative enough, and its finite element model needed for simplification. FSW trials were conducted on an Al6061 aluminum plate, the welding process of FSW was simulated with Forge software. The results show that the force and temperature in the welding process have high sensitivity with the friction coefficient. The size of the contact and friction surfaces can be calculated using ALE algorithm. The forces of norton friction model are in good agreement with the experimental results. The friction coefficient μ calculated by coulomb model is 0.3.