Modeling of rate-dependent damping capacity of one-dimensional superelastic shape memory alloys

摘要

Recent experimental tests showed that shape memory alloys have a strong dependence of stress-strain curve on the strain rate. This rate-dependent phenomenon is mainly due to the temperature variation of shape memory alloys caused by the latent heat release/absorption during the forward/reverse phase transformation. Since there is an increasing use of shape memory alloys for civil engineering like seismic application, the complex rate-dependent properties, such as the propagation stress and the damping capacity, should be carefully analyzed. This article studies the rate-dependent stress-strain curve, especially the damping capacity, of one-dimensional NiTi shape memory alloys by using a linear model and a nonlinear model taken the rate-independent driving force in the micromechanics-inspired constitutive model. Compared with the experimental data and previous work, both models use fewer material parameters and can easily describe the trend of damping capacity with respect to the strain rate. For their clear physical meaning and simple mathematical expression, both models are useful tools for the dynamic design and simulation of superelastic shape memory alloys in practice.