CONSTITUTIVE MODELLING OF SHAPE MEMORY ALLOYS BASED ON A FINITE STRAIN DESCRIPTION

Abstract

This paper presents the shape memory phenomena, and their crystallographical background. Furthermore a new model which is able to reproduce the basic responses of shape memory materials on both micro- and macrostructural aspects is also presented. The model is based on a local finite strain continuum description. A multiplicative decomposition of the total deformation gradient is used which involves elastic, plastic and phase transitional parts. The latter is given from microstructural measurement. For the elastic behavior of the material a coupled hyper-hypoelastic model and an objective logarithmic rate developed recently are used. Finally a constitutive equation is presented which consists of the kinetics of phase change process given by thermodynamical basis.