Thermomechanical and electrical response of a superelastic NiTi shape memory alloy cable

Abstract

Superelastic shape memory alloys are a unique class of smart materials that can recover up to 6% strains. Due to their appealing properties such as high energy dissipation and corrosion resistance, several researchers have assessed the use of such materials in numerous applications ranging from biomedical to civil engineering. This article investigates the thermomechanical and electrical response of a NiTi shape memory alloy cable with a complex configuration subjected to cyclic loading of various strain amplitudes ranging from 3% to 7%. The cable consists of several multi-layered strands with a cumulative outer diameter of 5.5 mm. The thermomechanical results indicate a good correlation of the change in cable temperature with the applied strains and maximum stresses. The temperature history can be used to map the degradation pattern of the shape memory alloy cable. In addition, due to the complex geometry of the cable, the global electrical resistance change does not predict the strain/stress state of the cable; however, it can be used to predict the onset of phase transformations.