On intrinsic time measure in the modeling of cyclic behavior of a Nitinol cubic block

Abstract

In this paper, the cyclic behavior of a superelastic-plastic nitinol cubic block is described by using the Bouc-Wen model coupled to an intrinsic time measure other than clock time, which governs the behavior of the materials. As a consequence, the thermodynamic admissibility of the Bouc-Wen model is provided by the endochronic theory of plasticity. The role of the intrinsic time measure is described by capturing the stiffness and strength degradation and the opposite phenomena. Such behavior is due to the permanent-strain addition of residual martensite and alterations in the properties of the texture during phase transformation.