Sensitivity of Seismic Applications to Different Shape Memory Alloy Models

Abstract

Shape memory alloys (SMAs) are known for their superelastic properties, which have been exploited in numerous applications in the biomedical, aerospace, and commercial fields. More recently, these materials have been evaluated for applications in the area of earthquake engineering. One key question that arises when using these materials is the appropriate constitutive material model to use to capture the highly nonlinear behavior of SMAs. This paper explores the effect of using different SMA constitutive models on the resulting response of systems using SMAs. A sensitivity analysis is conducted by using three SMA models with various levels of complexity. The models are implemented in a single-degree-of-freedom system and subjected to three groups of earthquake records with various characteristics. Considering a more accurate trend in modeling incomplete cycles in SMAs has little impact on the structural response. The strength degradation and residual deformation seem to be of more importance than the sublooping behavior. The response is more sensitive to the cyclic effects in the case of records with long durations or large intensities.