On Behaviors of Functionally Graded SMAs under Thermo-Mechanical Coupling

An analytical solution is obtained for the Functionally Graded Shape Memory Alloy (FG-SMA) composites subjected to thermo-mechanical coupling. Young's modulus and thermal expansion coefficient of the material are assumed to vary in different forms of power function through the thickness, with the Poisson's ratio being constant. An SMA constitutive model is combined with the averaging techniques of composite to determine the mechanical properties of the FG-SMA composites. Different phase transformation steps and the corresponding stress distributions through the thickness direction are given. The results show that the average stresses decrease as the transformations proceed.