Phase Transformation of Anisotropic Shape Memory Alloys: Theory and Validation in Superelasticity

Dimitris Chatziathanasiou (1) , Yves Chemisky (1) , Fodil Meraghni (1) , Georges Chatzigeorgiou (1) , Etienne Patoor (1)

1 LEM3 - Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux

In the present study, a new transformation criterion that includes the effect of tension–compression asymmetry and texture-induced anisotropy is proposed and combined with a thermodynamical model to describe the thermomechanical behavior of polycrystalline shape memory alloys. An altered Prager criterion has been developed, introducing a general transformation of the axes in the stress space. A convexity analysis of such criterion is included along with an identification strategy aimed at extracting the model parameters related to tension–compression asymmetry and anisotropy. These are identified from a numerical simulation of an SMA polycrystal, using a self-consistent micromechanical model previously developed by Patoor et al. (J Phys IV 6(C1):277–292, 1996) for several loading cases on isotropic, rolled, and drawn textures. Transformation surfaces in the stress and transformation strain spaces are obtained and compared with those predicted by the micromechanical model. The good agreement obtained between the macroscopic and the microscopic polycrystalline simulations states that the proposed criterion and transformation strain evolution equation can capture phenomenologically the effects of texture on anisotropy and asymmetry in SMAs.

Mots clés: Shape memory alloys; Superelasticity; Anisotropy; Tension–compression asymmetry; Transformation criteria; Evolution equation

Domaines: Matériaux; Mécanique [physics.med-ph]; Matériaux et structures en mécanique [physics.class-ph]; Mécanique des matériaux [physics.class-ph]; Mécanique des solides [physics.class-ph]

Dimitris Chatziathanasiou, Yves Chemisky, Fodil Meraghni, Georges Chatzigeorgiou, Etienne Patoor. Phase Transformation of Anisotropic Shape Memory Alloys: Theory and Validation in Superelasticity. Shape Memory and Superelasticity, 2015, August, pp.1-16. ⟨10.1007/s40830-015-0027-y⟩. ⟨hal-01196348⟩