Longitudinal and Lateral Stress Measurements in NiTi under One-Dimensional Shock Loading

Abstract

This paper investigates the influence of the impact stress on the magnitude of the shear stress under one‐dimensional shock loading. The shear stress is calculated from the measured longitudinal and the lateral stresses. New data in terms of shock stress, particle velocity and shock velocity has been gathered. Results indicate that the lateral stress has a positive dependence on the impact stress. A general decrease of the lateral stress was also observed immediately after the impact, while the longitudinal stress remains constant for the duration of the pulse length. This suggests that the shear strength increases behind the shock front. This decrease had been found to reach a constant value for the specimens impacted at lower stress. A complex mechanism of deformation behind the shock front during loading was thus reveals. This limit, related to the inflexion point noted on the Hugoniot (Us‐up), seems to be an effect of the martensitic phase transformation undergoes by the material.