Constitutive model taking into account the strain rate for uniaxial NiTi shape memory alloyunder low velocity impact conditions

Abstract

Under external impact load, due to the high strain rate at which a shape memory alloy(SMA) is loaded, the stress–strain behaviour under impact conditions differs from that atquasi-static loading as a consequence of the self-heating of SMAs at high strain rateloading.The present paper presents a constitutive model based on that of Liang and Rogers that iscapable of representing the uniaxial superelastic stress–strain behaviour of an SMA wireunder low velocity impact conditions. The strain rate dependence is accomplished by atemperature estimation method based on experimental observations under structuralimpact conditions achieved by the tensile impact technique; good agreement is observedwith experimental results.