Abstract
Damage problem occurring in quasi-isotropic composite laminates subjected to low velocity impact of foreign object is analytically studied. The damaged portion was modelled as piled equal-thickness circular plates where delaminations do not open. This assumption is a crude but mechanically acceptable approximation of the impact damage problem. Closed-form expressions of displacement and energy release rate are obtained in terms of applied force for simply-supported and fixed boundary conditions, where the effect of transverse shear is considered. The solution helps us to clearly understand the fundamental mechanism of impact damage problems, despite the solution being valid only at the initial stage of damage growth owing to the strong geometrical nonlinearity of the delaminated portion.
