Multi-mode wave propagation in damaged stiffened panels

Abstract

SUMMARY This paper addresses the issue of defect signature in stiffened panels at medium frequencies. With a tool for estimating the wave propagation characteristics of two-dimensional structures by k-space analysis, namely the Inhomogeneous Wave Correlation, the estimation of wavenumbers for waves propagating in stiffened panels can be achieved. Here, the method is employed with the sparse-simulated normal displacements of a set of stiffened panels. New insights into the use of their k-space behavior are hence highlighted. The guided wave behavior, which starts to appear at medium frequencies, can be extracted and treated in order to detect the presence of damage through a multi-modal wave propagation analysis in stiffened panels. The sensitivity of guided waves to defects in stiffened panels at medium frequency range is studied numerically, and the phenomena observed are explained with an energy diffusion analysis of waves propagating in stiffened panels. Copyright © 2011 John Wiley & Sons, Ltd.