Identification of a Nonlinear Beam : Proposition of an Identitication Technique

Abstract

As a basis for developing an identification technique of nonlinear distributed systems based on their dynamical responses, an identification technique which is applicable to a simple example of nonlinear distributed systems is proposed. The example taken up is a simply supported beam vibrating with large amplitudes. The basic procedures of the proposed technique are ( 1 ) measuring periodic responses of the beam to periodic external forces, ( 2 ) determining modal coordinates using the responses and based on the modal functions of the corresponding linear beam, and ( 3 ) determining the modal equations, including nonlinear terms, using the principle of harmonic balance. Some numerical examples are given, and the proposed technique is shown to be applicable.