An experimentally-fitted thermodynamical constitutive model for polycrystalline shape memory alloys

Abstract

A phenomenological model for polycrystalline NiTi shape-memory alloys with a refined dissipation function is here enhanced by a thermomechanical coupling and rigorously analyzed as far as existence of weak solutions and numerical stability and convergence of the numerical approximation performed by a staggered time discretization. Moreover, the model is verified on one-dimensional computational simulations compared with real laboratory experiments on a NiTi wire.

Vectorized MATLAB Implementation of the Incremental Minimization Principle for Rate-Independent Dissipative Solids Using FEM: A Constitutive Model of Shape Memory Alloys

“…We briefly summarize the core constitutive model for shape memory alloys originally introduced in [22,23] and further refined in [24][25][26]. Let us note that more experimental details on this important class of functional materials can be found in [27], for example, and a great variety of constitutive models tackling the peculiarities of their thermomechanical response can be found in the literature (e.g., the recent works of [28][29][30][31][32][33]).…”

“…Thus, it is a priori known within each time step and each element of triangulation. Let us note that the uniform temperature distribution within the body is assumed in the present implementation; the necessary modifications toward a full thermally coupled model were elaborated upon in [26].…”