A Nonparametric Identification Technique for Nonlinear Vibratory Systems : Proposition of the Technique

A new technique for identifying nonlinear systems is proposed. The basic procedures of this technique include (1) dividing the regions of displacement and/or velocity into small subdomains, and expressing the restoring force or damping force in a piecewise manner over each subdomain, (2) gathering dynamical data of a periodic external force applied to the system as well as those of periodic oscillations induced by it and (3) applying the principle of harmonic balance. To evaluate the applicability of the proposed technique, we applied it to some typical nonlinear systems with smooth nonlinearity as well as nonsmooth nonlinearity. In application of the technique, the dynamical data are generated numerically from the equation of motion of these systems. It has been shown that the proposed technique identifies the systems very well.