Abstract

The temperature dependence of the dynamic compressive stress-strain behavior of a NiTi shape memory alloy (SMA) has been determined at a strain rate of 4.35 × 10² s⁻¹ with a split Hopkinson pressure bar (SHPB) modified for obtaining the dynamic stress-strain loops at constant strain rates. The environmental temperature was varied from 0 to 50^∘ C, where the SMA exhibits superelastic behavior through stress-induced martensite (SIM). Experimental results show that both the loading and unloading portions of the stress-strain loop are significantly temperature dependent. Shape memory effect below the austenite finish transition temperature, A_f, and superelastic behavior above A_f are also observed at the high strain rate.

Keywords

shape memory alloy, high strain rate behavior, dynamic hysteresis, SHPB, Nitinol

Authors