Methodology for the estimation of material damping as applied to superelastic shape memory alloy mini-springs

• Published in: Materials & design 2019-01, Vol.161, p.124-135
• Main Authors: dos Reis, R.P.B., Silva, P.C.S., Senko, R., Silva, A.A., de Araújo, C.J.
• Format: Article
• Language: English
• Subjects: High damping metal; Shape memory alloys; Superelastic mini-spring; Vibration attenuation
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2018.11.012

This work presents an experimental methodology to estimate the material damping of superelastic helical mini-springs fabricated with superelastic shape memory alloys (SMA-SE). Moreover, the methodology provides a relatively inexpensive means for investigating the dynamic thermomechanical behavior of the NiTi SMA-SE mini-springs tested. This methodology is based on a resonance test in which the device is subjected to a mechanical reference system. We observed that four parallel mini-springs, each with a 0.033 g mass, have the capacity to reduce up to 6 dB of displacement amplitude (which represents an increase of 102% in hysteretic damping) in a mechanical system with a mass of 1485 g. Furthermore, a simplified analytical model is proposed based on observation of the frequency response function (FRF) of the mechanical system with the SMA-SE mini-springs. [Display omitted] •The combination of a vibration test with a signal analysis resulted in a methodology to measure loss factor and damping.•The dynamic behavior of NiTi mini-springs was revealed in a real experiment.•The functional analytical model shows a great fit with the FRF curves.•Depending on the parameters of the mechanism, self-heating can be beneficial for hysteretic damping.