LOW-VELOCITY IMPACT BEHAVIOR OF GLASS FIBER/EPOXY-ALUMINUM HONEYCOMB CORE SANDWICH COMPOSITES WITH VARYING FIBER ORIENTATIONS AND CORE THICKNESSES: EXPERIMENTAL STUDY

Abstract

This research experimentally investigates the low-velocity impact response of sandwich composites with glass fiber/epoxy face sheets and aluminum honeycomb cores, focusing on face sheet layup and core thickness. Three face sheet configurations, [0/0/0/0]s, [0/90/90/0]s, and [45/-45/-45/45]s, and honeycomb cores with thicknesses of 6, 10, and 15 mm were examined. Low-velocity impact tests were conducted according to ASTM D7136, and impact performance was evaluated through force-displacement responses and visible damage. The results showed that fiber orientation and core thickness significantly influenced impact resistance and damage mechanisms. Cross-ply specimens exhibited higher initial peak force resistance, whereas angle-ply specimens showed a more progressive and ductile failure behavior with enhanced energy dissipation over a larger displacement range. Increasing core thickness reduced impact energy transmission to the lower regions and decreased damage severity in the lower face sheet. These findings demonstrate that appropriate selection of face sheet orientation and core thickness can improve the impact performance of sandwich composites for aerospace, automotive, and marine applications.