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利用符合弹塑性本构关系的数学模型,施加高斯旋转曲面体热源,建立了符合实际激光焊接过程的有限元分析模型。通过改变激光功率、焊接速度、光斑直径的取值,探讨TC4钛合金横向残余应力的变化规律。通过分析残余与瞬态应力分布,揭示激光焊接塑性应变的形成与横向残余应力的分布规律。结果显示,激光焊接规范改变对接头横向残余应力的影响有限,TC4钛合金激光焊接头横向残余应力以压应力为主,且峰值不大,只有试板两端出现了不利的横向残余应力分布模式。热源作用瞬间,位于已冷却部位的热源后部产生了压缩塑性应变。
By using the mathematical model which accords with elastoplastic constitutive relation and applying the heat source of Gauss rotating surface body, the finite element analysis model which accords with the actual laser welding process was established. By changing the laser power, welding speed, spot diameter value, to explore the TC4 titanium alloy horizontal residual stress changes. By analyzing the distribution of residual stress and transient stress, the formation of plastic strain in laser welding and the distribution of transverse residual stress are revealed. The results show that the influence of the laser welding specification on the transverse residual stress of the joint is limited. The transverse residual stress of the TC4 titanium laser welded joint is mainly compressive stress, and the peak value is not large. Only the transverse residual stress distribution mode appears at both ends of the test plate . At the moment of the heat source, the compressive plastic strain is generated in the rear part of the heat source in the cooled part.