NONLINEAR MODAL COUPLING IN PLANAR AND NONPLANAR RESPONSES OF INEXTENSIONAL BEAMS

Non-linear inertia and curvature terms, as well as non-linear terms that couple flexural and torsional motions, can have a dominant role in the response of inextensional beams or beam-like structural members. In this paper the effect of modal coupling in the non-linear response of such members to a periodic excitation is analyzed and discussed. The analysis presented is based on a set of consistent differential equations of motion that take into account non-linear geometric effects. They include non-linear contributions from the beam's curvature and torsion expressions, and from inertia terms. Examples of amplitude-frequency response characteristics for cantilevers and for clamped-pinned/sliding beams are presented. © 1990.