On the characterization of the compressive response of shape memory alloys using bending

Abstract

Determination of material parameters of metals/polymers under compressive loadings has been sometimes an onerous issue especially for thin sheets and wires. In the present paper, an approach is presented to determine the compressive material constants of the shape memory alloy (SMA) sheets by employing four-point bending tests. A three-dimensional (3D) asymmetric model is presented and implemented in COMSOL software. An SMA strip showing pseudoelasticity at the ambient temperature is trained under tensile loading, and the experimental results are used together with the model to determine the tensile material parameters of the specimen. On the other hand, a sample is subjected to four-point bending, and, after training, the strain distribution at the lateral surface of the sample is captured by using digital image correlation method. The empirical results for bending are utilized along with 3D simulations to determine the compressive material parameters of the specimens. The approach is finally validated by experimental data, and it appears to provide a reliable procedure for the compressive characterization of SMAs. The present research enables users to avoid performing susceptible compression tests and also empowers them to study the compressive mechanical response of a material during training cycles under quasi-static/adiabatic conditions.