On transition of delamination growth behaviour for compression loaded composite panels

This paper presents a combined numerical and experimental study of slender composite panels loaded in compression with artificial delaminations at two different depths. The study was motivated by finite element analyses where this change in delamination depth induced a transition in the direction of delamination growth along with a change in the basic fracture modes and st ability. Tests were then carried out to verify the transition in delaminati on growth. The predicted transitions were to a large extent also seen in th e tests. The paper gives an outline of the computational model, which inclu des contact between delaminated members, calculation of energy release rate with fracture mode separation by an approximate as well as a reliable meth od for general layups, and moving mesh scheme to account for delamination g rowth. The experimental work includes monitoring of delamination growth by C-scan and acoustic emission along with a detailed fractographical study. T he correlation between experimental observations and computed results are d iscussed in detail. (C) 2001 Elsevier Science Ltd. All rights reserved.