Mesoscale Analysis of Translaminar Fracture in Thin-Ply Laminates

Abstract

Translaminar fracture toughness is a key property that determines the notch sensitivity and the damage tolerance of fibre-reinforced composites. By establishing a novel downscaled compact tension specimen configuration, designed for 4D synchrotron radiation computed tomography, a comprehensive perception of developed failure mechanisms can be attained. In this study, first, an initial finite element model, based on limited literature data for a compact tension of a [90/0]8s T300/913 carbon-epoxy laminate [1] is developed. Next, the cohesive law parameters between 0°/0° plies in a [902/0/902/0/902/0/902] thinply HS40/736LT laminate are directly extracted from in-situ synchrotron radiation computed tomograms of miniaturized compact tension specimens. The interlaminar (90°/90°) parameters are obtained from double cantilever beam test results on a similar material system. To accurately predict the ð‘…-curve, the crack extension and crack opening displacements, in both 90° and 0° plies, were captured in a multi-linear cohesive law. Consequently, in the proposed finite element approach, two distinct cohesive surface definitions are assigned to the fracture plane. The numerical results confirm the lagging crack fronts in 0° plies.