A preliminary investigation of excitation signal parameters on the detection of delamination in composite plates is presented. Composite plates typical of aerospace applications are used and excitation is provided through integrated PZT actuator. A scanning laser vibrometer is used for recording structural responses. Experimental results at three frequencies (15, 18, and 20 kHz) and two pulse widths (3.5 and 5.5 cycles) show the significant effects of incident Lamb waves on damage signature. Numerical studies using a commercial finite element code (ABAQUS) show good correlation with experimental results with appropriate level of structural damping.
This paper presents the detection of delamination in composite plates using the Damage Force Indicator (DFI) method. The global dynamic stiffness matrix of the healthy structure is obtained from Wavelet Spectral Finite Element (WSFE) model condensed to the degrees of freedom consistent with experimental measurements (out-of-plane displacements). The displacement vector for the damaged structure is measured using a scanning laser vibrometer. It is shown that the DFI method gives correct identification of damage.
Wavelet Spectral Finite Element (WSFE)Conventional finite element method (FEM) is not suited for wave propagation problems since the element size should be comparable to wavelength which is very small at high frequencies.Typically, 20 elements should span a wavelength for accurate predictions. This results in large
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.