On crushing responses of filament winding CFRP/aluminum and GFRP/CFRP/aluminum hybrid structures

This study aims to explore the crushing characteristics and failure modes of multiple filament winding hybrid tubes. Two types of hybrid tubes, namely Glass fiber reinforced plastics (GFRP)/carbon fiber reinforced plastics (CFRP)/aluminum (Al) hybrid tubes and CFRP/Al, were fabricated by the filament winding process. The typical load-displacement curves, failure modes, effects of winding plies, winding angle and interaction on crashworthiness were explored. It showed that the failure modes of hybrid specimens were predominated by progressive brittle crack, delamination mode in CFRP layers and diamond failure mode in aluminum tube. Increasing hybrid plies increased the specific energy absorption (SEA), energy absorption (EA) and peak crushing force (PCF). The PCF of the hybrid tubes decreased with increasing CFRP winding angle from 30° to 60° (winding angle of 0° was along the axial direction of the tube) while the hybrid tubes with the winding angle of 45° showed the highest SEA and EA. A theoretical analysis was conducted on the effect of interaction on load bearing capacity and it is showed that the interactions between different materials can effectively enhance energy absorption. A comparison among the filament winding, vacuum bag forming and nested manufacturing processes was performed and the filament winding technique exhibited the highest improvement in crashworthiness of CFRP/Al hybrid tubes.