Characterizing the nonlinear behavior of a pseudoelastic oscillator via the wavelet transform. (January 2016)

• Record Type: Journal Article
• Authors: Piccirillo, Vinicius; Balthazar, José M; Tusset, Angelo M; Bernardini, Davide; Rega, Giuseppe
• Is Part Of: Proceedings of the Institution of Mechanical Engineers. Volume 230:Number 1(2016)
• Page Start: 120
• Page End: 132
• Publication Date: 2016-01
• Subjects: Nonlinear dynamics -- shape memory materials -- nonideal system -- wavelets -- Scale index -- 0-1 test; Mechanical engineering -- Periodicals; 621.05
• DOI: 10.1177/0954406215589842
• Languages: English
• ISSNs: 0954-4062

Abstract

The nonlinear dynamics of a shape memory oscillator (SMO) subjected to an ideal or nonideal excitation is studied. The restoring force of the oscillator is provided by a shape memory device (SMD), described by a thermomechanical model capable of reproducing the hysteretic behavior via the evolution of a suitable internal variable. Due to nonlinearities in the model, the SMO can exhibit periodic or non-periodic behaviors. The effects of the external sources on the response of SMO are studied through the scalogram analysis of continuous wavelet transform by using a new measure, called the Scale index (Benitez R, Bolos VJ and Ramirez ME. A wavelet-based tool for studying non-periodicity. Comput Math Appl 2010; 60: 634–641). Numerical results show that the Scale index can successfully detect the behavior of the system when the signal is periodic or nonperiodic, and distinguish between them in a way consistent with the indications provided by the alternative 0-1 test.