Abstract：The important relationships among stress, strain, temperature, electrical resistance and phase transformation of NiTi shape memory alloy (SMA) was synthetically tested and analyzed by various combinations of parameters. A physical model was established to describe the experimental stressstrain curves of SMA, and numerical simulations were performed. Several testing methods were proposed for the need of material evaluations and smart structure developments. Experimental results show that a series of unusual changes on physical and mechanical properties of SMA occur when martensitic, especially R(rhombohedral), phase transformation emerge, and that the constitutive relationship of SMA is highly non-linear. Numerical results are in good agreement with experimental dataIt is an important and effective method to measure stress, strain, electrical resistance and temperature synthetically for studying properties and structural variations of SMA.
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