Development of simple evaluation system for Hugoniot of polymethyl methacrylate

The Hugoniot shock wave velocity \((U_{\textrm{S}})\)–particle velocity \((u_{\textrm{p}})\) curve of polymethyl methacrylate (PMMA) was measured in an experiment using only 2.5 g of a high explosive. The thickness of the plate was varied to accurately determine \(U_{\textrm{S}}\) at an arbitrary position in the PMMA. Image analysis was conducted to obtain the x–t diagram of shock wave propagating in PMMA along the axis of the explosive, and its derivative was used to obtain the on-axis \(U_{\textrm{S}}\) at an arbitrary location. Using the pressure measurement results and \(U_{\textrm{S}}\) values, the Hugoniot \(U_{\textrm{S}}\)–\(u_{\textrm{p}}\) curve of PMMA was obtained by calculating \(u_{\textrm{p}}\) from the momentum conservation law. The results are in very good agreement with the reported values for flat-plate impact experiments conducted using an impact gun. It was found that the Hugoniot \(U_{\textrm{S}}\)–\(u_{\textrm{p}}\) curve of PMMA on the low-pressure side \((u_{\textrm{p}} < 0.5\, {\textrm{km}}/{\textrm{s}})\) can be evaluated with high accuracy using a simple measurement method that does not use plane waves.