激光诱导AZ31B镁合金薄板动态响应实验研究

Experimental research on laser-induced dynamic response of AZ31B magnesium alloy sheet

为分析在激光冲击波作用下AZ31B镁合金薄板背面的动态响应,采用聚偏氟乙烯贴片传感器与数字示波器对强激光诱导的冲击波进行测量,得到压电波形,结合冲击波的传播特性,对弹塑性双波的传播规律进行了研究。结果表明:激光诱导的材料动态响应是快速的;压电波形图反映出的弹性前驱波与塑性加载波传播到靶材背面的时间与理论时间相符;弹性前驱波能量小引发的波形振幅较小,紧随着的塑性加载波能量大并引起较大振幅波动,弹塑性双波卸载过程与紧接着的加载过程导致了压电信号的波动振幅提高。

To analyze the dynamic response of the back of AZ31B magnesium alloy sheet to laser shock wave, the laser induced shockwave was measured by PVDF patch sensors and a digital oscilloscope and then piezoelectric waveforms were got. The propagation law of elastic and plastic wave structure was studied combined with shock wave propagation characteristics. The results indicate that the laser induced dynamic response of the material is transient. The time of elastic precursors wave and plastic load wave propagate to the back of the sheet is reflected by the piezoelectric waveforms. Which corresponds to the time of the theory. The waveform amplitude triggered by elastic precursor wave is small while the following plastic load wave causes larger amplitude fluctuations because of its larger energy. The loading process and unloading process of the waves have led to the amplitude increase of the piezoelectric signal