Finite element analysis of anew shape memory alloy composite actuator

摘要

The present paper proposes a non-linear finite element model for the transient response of a new shape-memory-alloy actuator. The actuator has a plane beam configuration composed of a matrix material with SAM sheets or wires embedded in and/or bonded to the matrix part. Due to large shear stresses and deformations, the model is developed based on a higher order shear deformation beam theory together with the Von-Karman strain field. A one-dimensional constitutive equation with non-constant material functions together with linearized phase transformation kinetics is used for the thermo-mechanical behavior of the SMA actuator. The constitutive and phase transformation kinetic equations make distinction between the stress-induced and temperature induced martensite fractions. The finite element model is general and in this paper it is applied to a cantilever SMA composite actuator with solid rectangular cross section. The results give the time-dependent structural responses of the actuator including axial deformation and lateral deflection. Also, the transient temperature response and martensite fraction in SMA layers are demonstrated.