Finite Elements Simulation of Mechanical Behaviour of Shape Memory Alloys Coupled with a Non-Stationary Thermal Field

The main deformation mechanism of shape memory alloys (SMA) are related to martensitic transformation and/or martensitic reorientation. These phenomena lead to heat production resulting from the transformation and/or from internal dissipation processes. As the SMA behaviour is strongly temperature dependent, its modelling has to take into account thermomechanical coupling. A 3-dimensional finite element code has been designed for that purpose. The quasi-static mechanical behaviour is described through the temperature dependent elastohysteresis model. Large displacements and large deformations are considered. The numerical problem is strongly non-linear and an implicit resolution scheme has been adopted. Two coupled thermomechanical calculations are presented. The first one deals with the one-way memory effect of a cantilever beam. The second one simulates the non-stationary thermal and mechanical fields of this beam during a near-adiabatic pseudoelastic bending