Investigation of Impact Response of Composites with Projection Moiré Enhancement

As a method for measuring full-field out-of-plane displacement, projection moiré provides high measuring quality with simple experimental setup. Based on an image processing program developed by Heredia and Patterson, this article presents the implementation of projection moiré in low-velocity impact testing. Results from projection moiré agree reasonably well with those obtained from the commonly used load cell method. In an attempt to better document composite response to impact loading, the possibility of correlating the external out-of-plane displacement measurement with the internal delamination is discussed. The technique is further applied to composites with various microstructures, including laminated, two-dimensional woven and quasi-three-dimensional (Q3D) woven composites. Projection moiré is able to provide some insights of the delamination propagation of the composites under impact loading.