Ambient effect on damping peak of NiTi shape memory alloy

We report the effects of ambient condition and loading rate on the damping capacity of a superelastic nickel-titanium shape memory alloy during stress-induced martensitic phase transformation with release and absorption of latent heat The damping capacity was measured via a tensile loading-unloading cycle in the strain-rate range of 10(-5)-10(-1)/s and three ambient conditions still air and flowing air with velocities of 2 m/s and 17 m/s. It is found that. for each ambient condition. the maximum damping capacity (damping peak) is achieved at the strain rate whose loading time (t(gamma)) is close to the characteristic heat-transfer time (t(h)) of the ambient condition (C) 2010 Elsevier BV All rights reserved