Experimental Investigation of Phase- Dependent Resistivity and Poisson's Ratio in Shape Memory Alloy Wires: Dataset of Experiments

This dataset belongs to a paper published by Smart Materials and Structures with the reference SMS-118393 Abstract: Thermal shape memory alloy (SMA) wires undergo a contraction during the phase transformation from Martensite to Austenite. They serve as an alternative to conventional actuators such as electric motors, pneumatics, and hydraulic actuators, due to their high energy density and silent operation. Additionally, SMA as smart material comes with a characteristic called “self-sensing”, as their electrical resistance changes during the phase transformation. This enables the possibility of position sensing and actuator control without an external sensor. However, accurate modeling and prediction of SMA behavior requires precise knowledge of their material properties, including electrical resistivity and Poisson’s ratio. This study presents an experimental investigation on SMA wires, focusing on their electrical and mechanical properties. A presented test setup enables simultaneous measurements of wire diameter, mechanical load, and electrical resistance. Tensile tests on 300 µm diameter SMA wires in the Martensite and Austenite phases determine phase-dependent specific resistivity values and the stress coefficient of resistivity. An actuator experiment, in which an SMA wire is activated against a spring, validates these previous results and provides further insight into the resistivity behavior during actuation. Finally, the temperature coefficient of resistivity is determined, and Poisson’s ratio is experimentally derived for both Martensite and Austenite.