Longitudinal and Lateral Stress Measurements in Shock Loaded Polyether Ether Ketone

Abstract

The shock response of poyether ether ketone (PEEK) has been investigated using manganin stress gauges mounted in longitudinal and lateral orientation to the impact axis. Measurements of the longitudinal stress with gauges at different positions within the shock assembly have determined the Hugoniot in terms of shock stress, shock velocity and particle velocity. It has been shown that the shock velocity has a simple linear response to particle velocity, in common with many but not all polymers. Measurements of lateral stress show a decrease behind the shock front, implying an increase in shear strength, possibly due to the viscoplastic nature of PEEK. Shear strength was also observed to increase with shock stress. A break in slope was observed at ca. 1.0 GPa, indicating a divergence between elastic and inelastic behaviour.