7075铝合金搅拌摩擦焊接头温度场及残余应力场的有限元模拟

Finite element simulation of friction stir welding temperature field and residual stress field of 7075 aluminum alloy

摘要: 根据搅拌摩擦焊特点及库伦摩擦做功理论,以厚度为6 mm的7075-T7351铝合金板材为研究对象,基于ANSYS有限元软件,建立了搅拌摩擦焊双热源三维有限元模型,研究不同转速、焊接速度对温度场及残余应力场的影响规律.结果表明,焊接过程峰值温度在500℃左右,接头最高温度出现在搅拌头后部大约5 mm处;接头残余应力以纵向残余应力为主,在垂直焊缝方向上呈M形分布,最大值约为150 MPa;当搅拌头转速一定时,随着焊接速度的增大,峰值温度减小,峰值纵向残余应力增大;当焊接速度一定时,温度随着转速的增大而增大,且转速越大,纵向残余应力分布越均匀.

Abstract: Based on the characteristics of the friction stir welding and Coulomb friction work theory, 7075-T7315 aluminum alloy flats with thickness of 6 mm were chosen as the study objects. Based on ANSYS code, a three dimensional numerical model with two heat flux inputs of friction stir welding were established. Moreover, the effect of welding speed and rotation speed on temperature and residual stress distributions were investigated.