A method for simultaneous identification of the full nonlinear damping and the phase shift and amplitude of the external harmonic excitation in a forced nonlinear oscillator

• Published in: Computers & structures 2013-04, Vol.120, p.77-85
• Main Author: Jang, T.S.
• Format: Article
• Language: English
• Subjects: Amplitudes; Damping; Full nonlinear damping; Harmonic excitation; Lack of stability; Mathematical models; Non-parametric identification; Nonlinearity; Oscillators; Phase shift; Phase shift and amplitude; Regularization; Simultaneous identification; Stability
• ISSN: 0045-7949; 1879-2243
• DOI: 10.1016/j.compstruc.2013.02.008

► We propose a new general method involving the nonlinear system identification. ► It concerns the simultaneous identification in a forced nonlinear system. ► It can identify the phase shift and amplitude of the external harmonic excitation. ► In addition to that, it can also identify the full nonlinear damping. ► The identification proposed in this study is non-parametric. We propose a new general method that is able to clarify the simultaneous identification of the full nonlinear damping characteristics as well as the phase shift and amplitude of the external harmonic excitation in a forced nonlinear single degree system. The method is the non-parametric identification based on the concept of zero-crossings regarding the system responses. It involves an integral equation of the first kind, resulting in the lack of stability properties. The difficulty of instability is overcome by the stabilization technique. The workability of the proposed method is demonstrated through a numerical experiment consisting of a highly nonlinear system.