Nondestructive detection of internal delamination by vibration-based method for composite plates

摘要

A method for locating internal delamination in multilayer composite plates is presented. A finite element method for composite plates is developed to investigate the relationship between delamination and change of modal parameters. The mechanism of the mode-dependent energy dissipation of composite plates is revealed by numerical analysis of delamination-induced variations of modal parameters. Experiments are carried out using piezoelectric actuator and accelerometer to measure the dynamic response to sinusoidal sweep excitation for several cantilever composite plates. The results show that the region of internal delamination in composite plates can be predicted according to the measured acceleration response and the computed modal strain energy.