强短脉冲激光冲击材料成形是一种高应变率的过程。很多已有测试手段由于响应带宽不够而无法进行有效测量。常用的任意面速度干涉仪(VISAR)价格昂贵、测试方法复杂,且存在条纹缺失。采用一种简单的光电测试系统探测出铝薄板在强短脉冲激光冲击下的高速变形过程。通过标定输出电压与变形量的关系,分析出薄板被冲击中心点的位移和速度,与文献仿真结果规律一致,计算出在8 J激光能量冲击时间内平均变形速度为8.49×104m/s。并由阻尼振动和弹性形变叠加的模型拟合出激光冲击薄板的形变过程,根据拟合系数计算出薄板的振动速度和塑性变形值,为分析和控制激光冲击变形工艺提供了依据。
The deformation process of material shocked by strong and short pulsed laser has high strain rate.Response bandwidths of many testing instruments are not wide enough to effectively measure the deformation process.The velocity interferometer system for any reflector(VISAR) commonly used to test dynamic deformation is complex and expensive.Especially it has the drawback of lacking stripes.A simple and novel optoelectronic measurement system is applied to measure the deformation.With the calibration of ratio of the output voltage and the deformation,the displacement and velocity of shock center can be worked out.The displacement and velocity law are similar with the simulation result reported.The average deformation velocity in shock period is calculated as 8.49×104 m/s.The analysis of the data,based on the fitting curve,shows that the deformation is superimposed the movement of damped oscillations and elastic deformation.Meanwhile,the vibration velocity and the plastic deformation of plate can be obtained through the fitting coefficient.These results provid a basis platform for the analysis and control laser shock deformation process.