Temperature Harmonic Analysis Of Austenitic Niti Under Dynamic Cyclic Loading

Abstract

– Due to their super-elastic behaviour, NiTi alloys operating above the phase transformation temperature are employed in several high-risk medical devices. Hence, the most advanced approaches shall be employed for their structural characterisation. This work investigates the thermo-mechanical response of NiTi alloys when analysed with infrared thermography. A nitinol strip was subjected to a dynamic sinusoidal loading under displacement control, with increasing average and amplitude ranges, within the austenite elastic state. Analysis of the harmonic content of the temperature signal in the frequency domain was carried out and compared with the predictions of the higher-order thermoelastic effect theory. Results indicate that, although the modulation of temperature signal is related to the sinusoidal load signal, the alloy response is different from traditional materials.