A corotational shell element for SMA devices

Aim of the present paper is the development of a new SMA shell finite element, based on the corotational formulation, accounting for the material and geometric nonlinearity. The corotational approach is based on the idea of separating rigid body motions from purely deformational ones. It is especially attractive in problems involving large displacements and small strains. A polar decomposition based corotational formulation is exploited and a combination of the discrete Kirchhoff plate triangle (DKT) and the optimal ANDES Template membrane triangle (OPT) is used as core-element, under plane stress assumption. A SMA constitutive model formulated in small strain framework is adopted, accounting for the pseudo-elastic as well as the shape memory effect. Applications are carried out for assessing the performances of the developed numerical procedure and to investigate on some interesting engineering examples.