多激光束增材工艺的热-机械行为演变模拟

Simulation of Thermo-mechanical Behavior Evolution of Multi-laser Beam AdditiveManufacture

建立了多激光束(主激光束、多束热处理激光束)的增材制造(AM)热力耦合模型,分析多激光束模式对AM过程中温度历史、整体应力演变历史及冷却至室温下等效塑性应力分布的影响,并与单激光束模式的模拟结果进行了对比。结果表明,不同激光模式下,熔覆层的温度历史、整体应力演变历史及等效塑性应力分布均呈类似的趋势。随着后处理激光束数量的增加,峰值温度、整体应力及等效塑性应力水平均有显著提升,更容易导致裂纹、断裂等现象发生。

AM thermo-mechanical coupling model with multi-laser beam(main laser beam,multiple post-processing laser beams)was established.Effects of the multi-laser beam mode on temperature history,overall stress evolution his⁃tory and equivalent plastic stress distribution during cooling were analyzed,and simulation results were compared with those of single laser beam mode.The results indicate that the temperature history,overall stress evolution history and equivalent plastic stress distribution of cladding layers present similar trends for both modes.As the amount of postprocessed laser beams increases,the peak temperature,overall stress and equivalent plastic stress levels are signifi⁃cantly increased,leading to cracks and fractures.