在对激光喷丸成形(LPF)机制分析的基础上,采用ABAQUS软件对激光喷丸成形过程进行了有限元数值模拟,分析了激光喷丸后板料的变形和残余应力场的分布情况。结果表明激光喷丸在板料表层的塑性变形层中诱导出压应力,在塑性变形层以下部位出现拉应力,这种应力分布形式打破了板料内部原有力系的平衡,促使板料发生弯曲变形,从而使板料内部应力重新分布以达到新的平衡,最终在板料厚度方向形成上下两面为压应力,而中部为拉应力的新的残余应力场。研究结果对理解激光喷丸成形过程及其本质,进行激光喷丸工艺参数的合理优化、板料变形过程的有效控制和进一步的实验研究具有指导意义。
The laser peen forming (LPF) is an emerging modern process of metal plate bending recently, which uses laser-induced shock wave pressure instead of metal ball to plastically bend metal plate, After the mechanisms of LPF were particularly analyzed, the process of LPF was simulated by using ABAQUS software, and the deformation and residual stress field of the shocked plate were studied. The results indicate that residual compressive stresses can be induced by laser peening in the plastic deformation layer of sheet's surface layer. At the same time, as internal material was restrained each other, tensile stresses were produced under the plastic deformation layer. The stress pattern broke the balance of primary force in the metal, so the plate was compelled to bend with a certain curvature. This resulted in the internal stresses in the plate redistributing to reach new stress equilibrium. Finally, a new residual stress field is gained in the plate, namely, both surface layers are all compressive stress, middle part is tensile stress. The study makes the process of LPF clear and has significance for the controlling of LPF and the further experiment investigation.