Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 02, 2019 - November 04, 2019
In this study, shock compression experiments are conducted on polycarbonate and PMMA to investigate their shock responses and spall behavior. The stress wave profiles propagate into samples are measured using PVDF piezoelectric film gauges embedded in samples. The spall strengths are determined by measuring free-surface-velocity profiles by means of the VISAR. Both measurements are simultaneously performed. The obtained relationship between shock velocity and particle velocity in PMMA show the non-linear nature below the particle velocity of 0.4 km/s indicating viscous effects. In the case of polycarbonate, its shock velocity shows bilinear relation with its particle velocity. Even though the tensile and compression strength of polycarbonate and PMMA show the strain-rate hardening, the spall strength itself does not show strain rate dependence in both materials. However, the spall strength obtained in both materials shocked above the point of discontinuity in each shock velocity – particle velocity relationship shows lower value than that obtained below that point. This result indicates that the microstructural change at shocked state effect on the spall behavior although the spallation occur the tensile stress state after compression release.
