Effect of Manufacturing Defects on Composite Energy Absorbers: Experimental Analysis

Abstract

Energy absorbers manufactured using reinforced composite materials absorb energy by undergoing a complex combination of failure modes such as matrix cracking, fiber fracture, delamination, sub-laminate bending, and fiber-matrix debonding. The presence of defects could undermine the load-carrying capabilities of these energy absorbers. In the current investigation, the effect of manufacturing defects on energy absorption capabilities and damage evolution of two different geometries, corrugated beams and cchannel stanchions, has been presented. The manufacturing defects investigated, introduced during specimen fabrication, include out-of-plane fiber waviness/wrinkling and delamination. Two different material systems and two different stacking sequences have been evaluated for each energy absorber type. Three-dimensional Digital Image Correlation (DIC) provides a comparison of damage evolution of pristine specimens and specimens with manufacturing defects.