Hierarchical design, manufacture and crushing behaviors of CFRP tubular energy absorbers

Abstract

Hierarchical topology is introduced to construct weight-efficient carbon fiber reinforced polymer (CFRP) tubular energy absorbers through filling small-diameter tubes into large-sized tubes. Crushing behaviors of the thin-walled tubes and the hierarchical tubes are investigated through quasi-static compression experiments and compared with each other. Large-diameter and long thin-walled tubes always fail at brittle modes with limited energy absorption (EA). The hierarchical tubes are crushed progressively and have excellent EA, for the mean crushing force (MCF) exceeds half of the peak force (PF) and the crushing distance is larger than half of the tube length. The improvement in the EA is attributed to the interactions among substructures at different levels which induce a ductile crushing mode. Taking into account the priority of low density, the hierarchical CFRP tubes are weight-efficient absorbers.