Size and training effects on the mechanical properties and hysteretic modelling of superelastic SMA plates

In this study, 16 tests were conducted on seven SMA plate specimens of three different sizes to investigate the effects of size and training on the cyclic tension-release performance of SMA plates. The study focused on the interaction between SMA plate size and key factors such as loading protocols. Key material parameters describing the hysteretic behaviour of SMA plates were derived, and a numerical model accounting for residual strain was developed and calibrated against the test data. Finally, to explore potential structural applications, a gusset plate connection incorporating SMA plates was proposed and analyzed using the calibrated model. The results showed that SMA plates of different sizes exhibited varying residual strains under identical strain conditions. Interestingly, the largest SMA plate did not exhibit the highest residual strain either before or after training, indicating a nonlinear relationship between plate size and residual strain. Additionally, the largest plate stabilized more rapidly during cyclic training, suggesting that larger SMA plates may offer improved stability with repeated use. The close agreement of hysteretic behaviour of the SMA plate specimens between the model predictions and the test data confirmed the model's accuracy. Numerical analyses of the gusset plate connection with SMA plates demonstrated that the SMA plates can enhance connection resilience by reducing residual deformation.