Influence of Strain Rate on Pseudoelastic Behavior in TiNi Shape Memory Alloy

The influence of strain rate on the pseudoelastic behavior associated with the martensitic transformation was investigated by tensile tests for TiNi shape memory alloy. The results were summarized as follows. The temperature rise due to the stress-induced martensitic transformation measured by a non-contact method is an order of magnitude larger than that measured through a thermocouple. The increase in the transformation stress with an increase in strain rete appears due to the temperature rise. The pseudoelastic behavior depending on strain rate is well expressed by the proposed constitutive equation considering the temperature variation. The proposed equation is useful for evaluation of pseudoelastic properties.