基于仿真的选区激光熔化工艺结构变形补偿设计优化

针对选区激光熔化工艺中残余应力造成的变形缺陷问题,介绍了一种基于有限元仿真的选区激光熔化工艺的结构变形补偿设计优化方法.以螺旋桨结构成型为例,首先建立了宏观尺度上基于有限元方法的热-力耦合仿真模型,然后分析了成型零件中的残余应力与变形分布规律,并提出了利用变形场反馈调整零件设计的几何结构的方法,通过多次反馈迭代,实现了成型后零件变形几何与期望几何之间的形状误差逐步减小.数值试验结果表明:经过变形场反馈调整4次,成型后的螺旋桨结构相较于期望几何结构的最大形状误差下降了94%;同时也发现,设计迭代过程中,零件成型后的残余应力与实际变形基本不变. 

Simulation-Based Optimization for Structural Deformation Compensation of Selective Laser Melting Process

Aiming at the deformation problem due to residual stress in the selective laser melting process, an optimization method for structural deformation compensation was introduced based on a finite-element simulation.Taking the forming of a propeller structure as a case study, a thermal-mechanical coupling macro-scale simulation model of the component based on the finite element method was first established, and the distribution characteristics of residual stress and deformation were analyzed lately.To obtain a finished part with a small enough shape error related to the desired geometry, an iterative method using the deformation field to adjust the initial design structure was proposed.Numerical experiment results show that, the maximum shape error between the finished propeller structure and the desired one cab be reduced by 94% after 4 iterations by the deformation-field feedback adjustment, in which it is also found that the residual stress and the real deformation of the finished part are essentially unchanged during the iterations.