Investigation of the localized twinning behavior of magnetic shape memory alloys using digital image correlation

Abstract:
In this work, we present an approach to model the hysteretic response of magnetic shape memory alloys (MSMA) to contracting and elongating loads using predefined bands over the length of the sample, motivated by the twinning stress of individual twin bands. To observe the twinning behavior of identified sections, optical images of MSMA samples are recorded under mechanical excitation and processed using digital image correlation (DIC). Several fitted models to predict the bands response to more complex inputs including inner hysteresis loops are derived, parameterized and compared with experimental results.