钛合金切削加工表面残余应力有限元仿真

采用Johnson- Cook失效准则,建立了钛合金的二维正交切削热-机械应力耦合有限元仿真模型,分析计算了不同切削条件下已加工表面残余应力的分布规律.结果表明:已加工表面层残余应力为拉应力,沿着深度方向由拉应力逐渐过渡到压应力.表面残余应力随着切削速度的增大而增大,在一定的前角变化范围内,随着刀具前角的增大,表面残余拉应力先增大后减小,而随着刀具后角的增大却减小.各加工参数对残余应力层的厚度影响都很小.

Finite Element Simulation on Residual Stress of Machined Titanium Alloy Surface

Based on Johnson-Cook failure criterion,it establishes 2D orthogonal TC4 cutting model of the coupled temperature-mechanical stress,analyzes the distribution of surface residual stress under different cutting conditions.The results show that the surface residual stress of workpiece is tensile stress.Along the depth direction,the tensile stress is transformed to the compressive stress.Surface residual stress increases with the in-creasing of the cutting speed,in a certain range of rake angle,the tensile residual stress on the workpiece surface increases with rake angle at first and decreases subsequently,while decreases with the in-creasing of the relief angle.All cutting conditions have little influence on the thickness of the residual stress layer.