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

Résumé

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.
Keywords: Shape memory alloy, nonlinear, tension-compression asymmetry, temperature