中空激光加载下板料位移和厚度分析

摘要

The changing process of sheet velocity,displacement and thickness are investigated by means of numerical simulation. The displacement and thickness of sheet are measured through experiments after hollow laser shocks, which is compared with solid laser shock. The results show that velocity and displacement of sheet metal in loading area first occur and expand,which makes central sheet form rapidly and has a maximum displacement. Thickness thinning first occurs at the boundary of the loading area and then expands,which makes the sheet thickness in central and loading area decreases rapidly. Section profile of sheet metal is Gaussian curve approximately after hollow laser shocks. Reduction of sheet thickness in central area reaches the maximum,followed by the one in loading area. The deformation uniformity of sheet after hollow laser shocks is better than that under solid laser shock. This research has a great significance in promoting laser shock formability.%采用数值仿真的方法，研究了中空激光加载下板料成形过程中位移和厚度参量的变化过程，通过试验对中空激光冲击成形后板料的位移和厚度进行了测量，并与实心激光下板料的位移和厚度进行了对比。结果表明，加载区域内板料首先获得速度产生位移并向外扩展，带动中心板料快速成形并产生最大位移；厚度减薄首先发生于加载区域边界并向外扩展，板料中心和加载区域内板料快速减薄。中空激光冲击成形后板料的截面轮廓呈高斯曲线分布，板料中心区域减薄最多，其次是加载区域，其变形均匀性优于实心激光冲击下的板料变形。研究工作对提高激光冲击成形性能具有重要意义。