Soft Body Impact Damage Tolerance of Laminated and 3D Woven Composites

Abstract

The Affordable Composite for Propulsion (ACP) program is investigating material designs and manufacturing processes which produce affordable and structurally acceptable parts for turbofan engine applications. In order to evaluate material architectures for engine structures susceptible to bird impact events, soft body impact tests were performed on laminated and 3D woven composite flat panels. Material architecture variables such as graphite/glass hybridization, stitching and type of stitch fiber for laminated composites, and ply-to-ply and through thickness interlock weaves for 3D materials were investigated. The primary test results of interest were damage resistance (velocity or energy to initiate measurable damage) and damage tolerance (resistance of the panel to propagation of existing damage). The results of these experiments are presented, and the behavior of the various material architectures are compared and contrasted. Material architecture variables which increase the soft body impact damage resistance and tolerance will be noted.