基于SPH方法的搅拌摩擦焊数值模拟研究

Numerical simulation research of friction stir welding based on SPH method

光滑粒子流体动力学(smoothed particle hydrodynamics,SPH)法是基于拉格朗日的一种无网格法,基于SPH方法使用ABAQUS软件进行AZ31B镁合金的搅拌摩擦焊数值模拟,通过改变搅拌头转速,研究残余应力和温度的分布。结果显示:焊缝两侧残余应力分布呈不对称,后退侧应力大于前进侧;应力曲线具有双峰特征,在焊接区域表现为拉应力;随着转速的增加,工件应力分布更加均匀;焊缝两侧的温度呈不对称分布,且前进侧高于后退侧,随着转速的增加,温度呈上升趋势;纵向温度曲线呈M形分布。模拟结果对实际焊接过程中焊接参数的选择具有一定参考意义。

Smoothed particle hydrodynamics(SPH)is a meshless method based on Lagrangian.ABAQUS software was used to simulate the friction stir welding of AZ31B magnesium alloy based on the SPH method.By changing the rotation speed of the stirring too,the distributions of residual stress and temperature were studied.The results show that the distribution of residual stress on both sides of the weld is asymmetrical,and the stress on the retreating side is greater than that on the advancing side;the stress curve has bimodal characteristics,showing tensile stress in the welding area;as the rotational speed increases,the stress distribution of the workpiece becomes more uniform;the temperature distribution on both sides of the weld is asymmetrical,and the advancing side is higher than the retreating side,and the temperature rises with the increase of the rotational speed;the longitudinal temperature curve presents an M-shaped distribution.The simulation results have certain reference significance for the selection of welding parameters in the actual welding process.