Thermally Induced Damage Initiation and Growth in Plain and Satin Weave Carbon-Carbon Composites

Abstract

Carbon-carbon woven composites were analyzed using three-dimensional finite-element analysis to predict the state of the composite after processing. Two types of weaves were examined: plain weave and eight-harness satin weave. Periodic boundary conditions for analyzing eight-harness satin weaves are derived herein. The effect of the stacking sequence of these weaves was investigated. Temperature-dependent material properties and a nonlinear damage model were used in the analysis procedure. Results indicate that there is a significant difference in the as-processed damage states and moduli of these composites for different stacking sequences. Damage initiated as transverse matrix cracks for all weave configurations. This lead to significant damage to the matrix pockets and, in some cases, to tow debonding and shear failure within the tows. In no case was fiber damage predicted.