On transition of delamination growth behaviour for compression loaded composite panels

Abstract

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 stability. Tests were then carried out to verify the transition in delamination growth. The predicted transitions were to a large extent also seen in the tests. The paper gives an outline of the computational model, which includes contact between delaminated members, calculation of energy release rate with fracture mode separation by an approximate as well as a reliable method for general layups, and moving mesh scheme to account for delamination growth. The experimental work includes monitoring of delamination growth by C-scan and acoustic emission along with a detailed fractographical study. The correlation between experimental observations and computed results are discussed in detail.