Methodology and some results of studying the influence of frequency on functional properties of pseudoelastic SMA

The mechanical loading frequency affects the functional properties of shape memory alloys (SMA). Thus, it is necessary to study effect in order use successfully these materials real structures. Based on pseudoelastic cyclic behavior, experimental methodology that allows testing NiTi wires stress controlled mode proposed. Cyclic tensile tests are carried out using universal machine STM-100 at room temperature with frequencies 0.1 Hz and 10 Hz. dependencies determined based experimentally obtained hysteresis loops. These comprise dissipated energy damping factor. It iis found increase results worsening properties, namely, decrease This caused by fact regions austenitic martensitic transformation under high absent. That is, austenite into martensite does not occur, stands for pseudoelasticity effect. Nevertheless, should be noted 100 times augments lifetime wire made alloy roughly 30%. maximum strain two first cycle, practically 5 after 200 cycles loading.