Analysis of Eigenfrequencies of a Circular Interface Delamination in Elastic Media Based on the Boundary Integral Equation Method

Abstract

The widespread of composite structures demands efficient numerical methods for the simulation dynamic behaviour of elastic laminates with interface delaminations with interacting faces. An advanced boundary integral equation method employing the Hankel transform of Green’s matrices is proposed for modelling wave scattering and analysis of the eigenfrequencies of interface circular partially closed delaminations between dissimilar media. A more general case of partially closed circular delamination is introduced using the spring boundary conditions with non-uniform spring stiffness distribution. The unknown crack opening displacement is expanded as Fourier series with respect to the angular coordinate and in terms of associated Legendre polynomials of the first kind via the radial coordinate. The problem is decomposed into a system of boundary integral equations and solved using the Bubnov-Galerkin method. The boundary integral equation method is compared with the meshless method and the published works for a homogeneous space with a circular open crack. The results of the numerical analysis showing the efficiency and the convergence of the method are demonstrated. The proposed method might be useful for damage identification employing the information on the eigenfrequencies estimated experimentally. Also, it can be extended for multi-layered composites with imperfect contact between sub-layers and multiple circular delaminations.

Analysis of an Interface Crack between Piezoelectric Semiconductor Coating and Elastic Substrate Structure

“…Taking into account the micro-crack damage situation of the material, a new piezoelectric thin-film interface model was developed to characterize the damage behavior of the interface by Rizzoni et al [30]. The dynamic behavior of elastic laminates with interface delamination and interaction surfaces was simulated using the boundary integral equation method [31]. Furthermore, the transient response of a piezoelectric interface crack under a mechanical impact and the problem of moving interface cracks [32,33], interface multiple cracks [34][35][36], and inhomogeneous piezoelectric interface cracks [37,38] were studied.…”

Damage assessment of laminated composites using unsupervised autonomous features

“…Its presence substantially impacts the stability, stiffness, useful operational life, and strength of laminated composites and is often the leading cause failure of the composite structures. [3][4][5] Hence, the timely prognostic of the laminated composite is crucial to ensure its safety in real-world applications, and to avoid catastrophic failure. To assess the health of the engineering structures, non-destructive testing methods (NDT) are usually applied for their structure health monitoring (SHM).…”