DAMPING BEHAVIOUR OF SHAPE MEMORY ALLOYS: STRAIN AMPLITUDE, FREQUENCY AND TEMPERATURE EFFECTS

✍ Scribed by M.C. Piedboeuf; R. Gauvin; M. Thomas

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 244 KB
• Volume: 214
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1998.1578

✦ Synopsis

An extensive study of the effects of frequency and strain amplitude as well as temperature on the damping behaviour of superelastic NiTi shape memory alloy wires was undertaken. A full factorial design taking into account the two-level interactions between these variables has been conducted. The dissipated energy and the loss factor were analyzed. Analysis shows that an increase in temperature has no effect on the dissipated energy while it decreases slightly the loss factor. Both however increase with the increase in strain amplitude. A maximum in dissipated energy and in the loss factor is observed around 0•1 Hz. Both factors then decrease as the frequency continues to increase. This behaviour is also strain amplitude dependent. A thermal analysis showed that the observed frequency and frequency-amplitude interaction effects are due to an important temperature variation produced by the energy generated during the transformation. Finally, a three harmonic Fourier sine series model is proposed to model the shape memory alloy dynamic behaviour. Frequency, amplitude and temperature effects are taken into account and dissipated energy and the loss factor can be determined from this model.