The stress-strain-temperature relation associated with the R-phase transformation in TiNi shape memory alloy was investigated from the phenomenological point of view. A set of constitutive equations consisting of the mechanical constitutive equation and of the transformation kinetics were presented to describe the shape memory effect, the transformation pseudoelasticity and the partial pseudoelasticity. The material constants in the theory were determined from the results of the tensile tests on TiNi wire specimens at various temperatures. The theory described well the stress-strain-temperature relation based on the R-phase transformation.
