Mode localization and frequency loci veering in disordered engineering structures

Vibration mode localization and frequency loci veering in disordered structures of aircraft engineering are discussed in this paper. Three T-type beam models of disordered horizontal tails with rear fuselage, a model of two disordered coupled control surfaces and a model of an aircraft with disordered external stores are adopted for the theoretical analysis. The matrix perturbation technique and the geometric theory are used to study the occurring mechanism of the two phenomena. Several simple criteria for predicting the occurrence of the mode localization and frequency loci veering are given. The theoretical prediction of the phenomena is in great agreement with that obtained through numerical calculations of characteristic solutions of the disordered structures. (C) 2000 Elsevier Science Ltd. All rights reserved.