Comportement dynamique des structures altérées.

Abstract

In this work, the effects of crack depth and crack location on the free and forced vibrations of cracked beam structures were investigated analytically by extending the Rayleigh method. The theory of Euler-Bernoulli beams is used to model the cracked beam and the crack is represented as a rotation spring according to the principles of fracture mechanics. The effects of crack depth and location on the natural frequency, shape of the mode and transverse displacement are presented in detail. The comparison between the present work and the results obtained in several cases of previous experimental, analytical and numerical studies shows a very good agreement. The theoretical results are very satisfactory and suggest that a practical method could be developed, which would allow considerable savings in terms of computational effort and costs associated with dynamic analysis and crack detection.