A NOVEL DERIVATION FOR MODAL DERIVATIVES BASED ON VOLTERRA SERIES REPRESENTATION AND ITS USE IN NONLINEAR MODEL ORDER REDUCTION

Abstract

This paper presents a novel derivation for modal derivatives based on the Volterra series representation of nonlinear structural systems. After reviewing the classical derivation, new modal derivatives are proposed based on the employment of the Volterra theory and the variational equation approach. It turns out that the gained new derivatives are almost identical to the conventional ones, except for the fact that a sum/subtraction of eigenfrequencies results in our definition. In addition to the novel derivation, some possible impacts and applications of the new derivatives are presented and discussed, pursuing the aim that the conceptual results are also useful for practical purposes.