SMA pseudoelastic finite strains. Theory and numerical application

A tridimensional finite element model of isothermal pseudoelastic deformati ons is proposed in order to analyze and predict the behavior of shape memor y alloys (SMA). To perform finite strain calculations, the mechanical model ing is based on a formulation in a non material rotating frame, The constit utive equations in a particular configuration are closed form of those deve loped with small strain assumption. This leads naturally to a numerical sch eme composed of an elastic prediction and a possible pseudoelastic correcti on. To insure the convergence of the equilibrium equation solving method, a consistent tangent operator with the stress calculation algorithm is defin ed. In the case of thin structures, the proposed model is consistent with t he zero normal stress condition within a three node shell element based on a mixed interpolation in order to avoid transverse shear locking. Numerical results are presented to show the accuracy of the proposed approach.