Numerical simulation for the behavior of superelastic shape memory alloys

摘要

Superelastic shape memory alloys (SMAs) are unique metallic materials that undergo substantial plastic deformations and recover their original conditions when stresses are only removed without any heat treatment. SMAs have currently become prevalent for application in structural engineering because this superelastic property contributes to entire construction system by mitigating the problem of permanent deformation. Notwithstanding many structural advantages, there exist relatively few investigations on the numerical modeling of these smart materials, which had been mostly used for nonlinear analyses. For this reason, this study mainly focuses on a one-dimensional (1D) constitutive model able to simulate the inherent behavior of superelastic SMAs, taking into account phase transformation between austenite and martensite. After discussing a possible approach for the solution scheme, numerical simulation results are compared to experimental data obtained from pull-out tests that are performed on SMA bars in order to validate the adequacy for the 1D constitutive material model presented. Furthermore, the user material model based on the solution algorithm of reproducing this superelastic behavior is applied to the structural analysis with a view to assure adequacy in practical use.