Influence of interaction parameters on laser shock wave induced dynamic strain on 7050 aluminum alloy surface

To study the effects of overlay and laser power density on dynamic strain, the dynamic strain induced by a pulsed laser shock wave on a 7050 aluminum alloy surface was measured using a polyvinylidene fluoride (PVDF) piezoelectric sensor. A dynamic strain model of the 7050 aluminum alloy surface under the pulsed laser shock wave load was established based on our hypothesis. The results showed that, under the influence of a constraining layer, the laser's thermal effect was negligible when the laser power density was higher than 1.4 GW/cm(2). When the material surface was loaded by the laser for 140 ns, a surface wave was detected by the PVDF sensor, but when the laser power density was less than 12.7 GW/cm(2), coupling between the shock wave and the surface wave did not occur. The dynamic stress-strain relationship curve of the 7050 aluminum alloy under the high strain rate of the pulsed laser shock wave was similar to the static stress-strain relationship curve of the 7050 aluminum alloy under static tensile conditions. The experimental results were consistent with the results of the dynamic strain model of the 7050 aluminum alloy surface under the pulsed laser shock wave load. (C) 2014 AIP Publishing LLC.