基于网格重剖分的搅拌摩擦焊接数值模拟及搅拌头受力分析

采用自适应网格方法,建立搅拌摩擦焊接过程的完全热力耦合热刚粘塑性有限元模型,模拟搅拌摩擦焊接过程中工件的温度场、变形场和搅拌头的受力。计算结果表明,温度场关于搅拌头的分布为非对称,焊接在前行侧的有效应变高于其返回侧;沿焊缝区域的温度场、应变场分布是由工件的上表面至底面,呈自上而下的顺序递减。对搅拌头反力曲线的研究表明,在相同的转速下,焊接速度越快,其反力越大;在相同的焊接速度下,转速越大,其反力越小;搅拌头的受力峰值产生在预热阶段结束和搅拌头开始移动的时刻,在给定搅拌头倾角的情况下,搅拌头的最高温度产生在搅拌头的后侧。

Adaptive re-meshing based numerical simulation of friction stir welding and tool force analysis

A fully coupled thermo-mechanical visco-rigid plastic FEM model for friction stir welding was established based on the adaptive re-meshing technique.The temperature field,material deformation and tool forces were simulated.Results indicate that the temperature distribution is asymmetric around the tool.The effective strain at the advancing side is higher than the one at the retreating side.Both the temperature and the effective strain decrease from top surface of the workpiece to the bottom in the region along the welding seam.Analysis shows that the tool force is increased with the increase of the transverse speed in certain angular speed.But the tool force is decreased with the increase of the angular speed in certain transverse speed.At the end of the pre-heating period,the tool force reaches its maximum.The maximum temperature on the welding tool can be found at the rear half of the welding tool when the tilt angle is given.