激光冲击波在铝合金薄板中传播特性研究

为了研究激光冲击波在铝合金薄板中的传播特性,采用数值仿真的方法,分析了不同节点路径下,冲击波在3003铝合金薄板中的传播特性。研究结果表明,激光加载初期,板料表面光斑边缘位置处应力最大,而板料表面中心区域仅为较小的波动,1000 ns后,表面波传播至板料上的凹模口对应位置,同时中心位置区域应力增大至200 MPa,塑性变形加大,板料变形不均匀,易出现减薄失效问题;沿激光冲击方向,经历60 ns压力波传播至板料自由面,并回传拉伸波,在102 ns左右,拉应力达到最大值1782 MPa,板料易出现层裂失效问题。因此针对激光冲击波在铝合金薄板中传播特性的研究对提高铝合金薄板激光冲击成形性能具有重要的意义。

Research on propagation characteristics of laser shock wave in aluminum alloy sheet

In order to research the propagation characteristics of laser shock wave in aluminum alloy sheet,numerical simulation method is used.The paper analyses the propagation characteristics of shock wave in 3003 aluminum alloy sheet through path of different nodes.The result shows that in initial phase of laser loading,maximum stress appears on the edge of laser spot on sheet surface while only small fluctuation occurs in central area.After 1000 ns,the stress in central area increases to 200 MPa when surface wave propagates to the position that corresponds to concave die.At the same time,plastic deformation increases while sheet deformation is uneven,which would cause thinning failure.In laser shock direction,the pressure wave propagates to the free surface of sheet and returns tensile wave after 60 ns.At about 102 ns,the tensile stress reaches maximum value of 1782 MPa,which is liable to cause spallation failure.The results are important for improving aluminum alloy forming performance by laser shock.