Application of one-dimensional phase transformation model to tensile-torsional pseudoelastic behavior of shape memory alloy tubes

摘要

The one-dimensional phase transformation model proposed by the author was applied to an analysis of bi-axial tensile-torsional pseudoelastic deformation behavior of a shape memory alloy (SMA) tube. In the one-dimensional phase model, virtual grains are sorted in order of energy required for transformation and the order of these grains is assumed to be unchanged irrespective of phases before and after the transformation. Accordingly, the transformation always takes place in the same order. Here a torsional stress induced martensitic phase was considered in addition to an austenitic phase and a tensile stress induced martensitic phase. Tensile and torsional stress-strain hysteresis loops for a pseudoelastic SMA thin tube were simulated. The simulated loops were in quantitatively good agreement with available experimental data for a pure tensile and a pure torsional strain loading. For combined loadings, the simulated loops qualitatively agreed with the experimental data.