Nonlinear analysis of shape memory alloy beam under the thermal and the mechanical loads

In this paper, the tension-compression asymmetry of shape memory alloys (SMA), subjected to the thermal and the mechanical loads, is sufficiently explored. Taking a basis of stress-strain relationship and a concern for critical phase transformation, a new simple model of mechanics is established. Through the deflection lines under different load conditions and the maximum deflection-bending moment curve, the effects of material nonlinearity and geometric nonlinearity on bending deformation of SMA beam are investigated. The results show that the neutral layer offset is related to the tension compression asymmetry coefficient and temperature. The phase transformation of SMA beam becomes more and more difficult as the increase of tension compression asymmetry coefficient and temperature. For the earlier phase transformation, material nonlinearity and geometric nonlinearity have little influence on beam deflection, but great in the late phase transformation.