基于固有应变的PBF-LB复杂曲面应力模拟及失真迭代优化

Stress simulation and distortion iterative optimization of PBF-LB complex surface based on inherent strain

金属激光粉末床熔化技术(PBF-LB)为航空航天复杂零件的制造提供了可行性和高效性,但成型过程中产生的应力和变形会影响零件的正常使用。利用固有应变法对PBF-LB成型过程进行模拟仿真,预测了内应力及变形,减少了试错次数,提高了打印质量和效率。针对复杂曲面零件设计了3种不同摆放及支撑打印成型方案,利用固有应变有限元分析法分析了预测应力趋势和变形分布,并对零件进行了失真迭代优化。对比优化前后结果发现最大正应力下降14%,等效应力下降17.9%。研究结果可以为PBF-LB工艺方案设计和优化提供参考。

The metal laser powder bed melting technology(PBF-LB)provides the feasibility and efficiency for the manufacturing of aerospace complex parts,but its forming process is easy to produce stress and deformation,which affects its use.Using the inherent strain method to simulate the PBF-LB forming process and predict the internal stress and deformation can greatly reduce the number of trial and error,and improve the printing quality and efficiency.Three different placement and support printing forming schemes are designed for complex curved parts.The stress trend and deformation distribution are analyzed and predicted by using the inherent strain finite element analysis method,and the distortion iteration optimization is carried out for the parts.Comparing the results before and after optimization,it is found that the maximum normal stress decreases by 14%and the equivalent stress decreases by 17.9%.The research results can provide reference for the design and optimization of PBF-LB process.