Transformation front in shape memory alloys

In this paper, the angle between the transformation front and the applied stress of four typical shape memory alloys (SMAs) is investigated analytically and numerically. As demonstrated, the relationship of θ against the applied stress varies according to the transformation strain of a particular SMA. The predicted angle of NiTi in the uniaxial tension is very close to the measured one reported in the literature. It is suggested that θ = 45° may be used as a parameter to classify plane stress problem.