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针对航空发动机空心涡轮叶片激光快速成形(LRF),建立了温度场/应力场瞬态模型,采用有限单元生死技术模拟了熔覆层的沉积生长过程.采用随动强化及米塞斯屈服准则进行了热弹塑性分析,通过间接耦合模拟了TC4钛合金空心叶片激光快速成形的温度场/应力场演变过程.结果分析表明,在TC4钛合金空心叶片激光快速成形过程中,随着熔池的移动和成形高度的增加,温度场和应力场动态演化,其中由于基座的冷却及约束作用和熔池加热及应力释放作用,激光快速成形空心叶片温度和应力/应变场沿高度(z轴)方向呈梯度分布.温度场上高下低,散热方向从上至下,从熔池到基座;应力场下高上低,叶根等效应力最大.空心叶片激光快速成形结束冷却到室温,残余应力与熔覆过程应力分布规律基本相同,只是叶片顶部等效应力有所提高.
Aiming at the laser rapid prototyping (LRF) of hollow turbine blade of aeroengine, a transient model of temperature field / stress field was established, and the deposition and growth process of cladding layer was simulated by the finite element method of life and death. The thermo-elasto-plastic analysis shows that the evolution of temperature field / stress field in TC4 titanium alloy hollow blades is simulated by indirect coupling.The results show that during the rapid prototyping process of TC4 titanium alloy hollow blades, And the increase of forming height, the dynamic evolution of temperature field and stress field, in which the temperature and stress / strain field of laser rapid prototyping hollow blade vary along the height (z-axis) direction due to the cooling and restraining effect of base and the heating and stress release of molten pool. A gradient distribution.The temperature field of high and low low, the cooling direction from top to bottom, from the molten pool to the base; stress field high and low, the root of the maximum equivalent stress.Hole blade rapid prototyping cooling to room temperature, residual Stress and cladding process stress distribution is basically the same, but the blade top equivalent stress has increased.