Thermomechanical characterization of functionally stabilized nickel-titanium-copper shape memory alloy

Abstract

Shape memory alloy hybrid composites have promise in realizing the 21st century goal of morphing structures. There is considerable work to be done in the development of characterization and modeling techniques for these materials. The proposed characterization methodology adapts existing standards to include previously omitted factors required for the numerical modelling of shape memory alloys and their integration into end-use applications. A nickel-titanium-copper (NiTiCu) shape memory alloy is characterized using these methods and then numerically modelled. Samples’ mechanical behaviour is shown to stabilize after 43 cycles of mechanical loading. Thermomechanical properties measured before and after stabilization are shown to vary inconsistently by up to 72%, demonstrating the need for stabilization for accurate thermomechanical characterizations and consistency in end-use applications. Physical experiments are numerically replicated in Abaqus\Standard using the measured properties. Sufficient correlation is shown for the design of shape memory alloy hybrid composites. The result of this work is a comprehensive thermomechanical characterization approach for shape memory alloys which can be used to develop morphing SMA hybrid composite structures.

Thermomechanical characterization of phase transformation surfaces for thin SMA wires

“…The SMA wire specimen can also be heated and cooled in an environmental air chamber (Iyer and Hubert, 2022; Prahlad and Chopra, 2003; Sahli and Necib, 2014). However, the thermal coupling between air and wire is relatively weak.…”