Elastic wave propagation and stop-band generation in stronglydamaged solids
Journal Title: Frattura ed Integrità Strutturale - Year 2014, Vol 8, Issue 29
Abstract
In this work, we study the propagation of elastic waves in elongated solids with an array of equallyspaceddeep transverse cracks, focusing in particular on the determination of stop-bands. We consider solidswith different types of boundary conditions and different lengths, and we show that the eigenfrequenciesassociated with non-localized modes lie within the pass-bands of the corresponding infinite periodic system,provided that the solids are long enough. In the stop-bands, instead, eigenfrequencies relative to localizedmodes may be found. Furthermore, we use an asymptotic reduced model, whereby the cracked solid isapproximated by a beam with elastic connections. This model allows to derive the dynamic properties ofdamaged solids through analytical methods. By comparing the theoretical dispersion curves yielded by theasymptotic reduced model with the numerical outcomes obtained from finite element computations, we observethat the asymptotic reduced model provides a better fit to the numerical data as the slenderness ratio increases.Finally, we illustrate how the limits of the stop-bands vary with the depth of the cracks.
Authors and Affiliations
G. Carta, M. Brun, A. B. Movchan
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