DELAMINATION AND FIBER BRIDGING MODELING IN COMPOSITE SAMPLES

Crack propagation in a long fiber composite material typically involve s the development of a fiber bridging which connects the two crack tip s, resulting in an increase of the crack-growth resistance, known as t he R-curve effect. The specific contribution of this paper is to accou nt for this effect within the framework of simple one dimensional mode ls and to perform efficient, simple, and complete numerical simulation s of crack propagation taking into account creation and transport of t he fiber nesting. The composite sample is modelled by an assembly of t hree beams and a density of damageable springs for the fiber bridging. With this type of modelling, we can separate the global dissipation i n the sample into two specific terms: one associated with crack tip pr opagation and one with degradation of the fiber nesting. We present re sults for classical Mode I and Mode II tests. using Double Cantilever Beam and End Load Split specimens.