| Abstrak/Abstract |
Brachyuran crab carapaces are protective, impact-resistant exoskeletons with elaborate
material microstructures. Though several research efforts have been made to characterise the
physical, material and mechanical properties of the crab carapace, there are no studies detailing
how crab morphologies might influence impact resistance. The purpose of this paper is to
characterise and compare Brachyuran crab carapace morphologies in relation to their impact properties,
using opto-digital, experimental and numerical methods. We find that crab carapaces with both
extended carapace arc-lengths and deep carapace grooves lose stiffness rapidly under cyclic impact
loading, and fail in a brittle manner. Contrarily, carapaces with smaller arc lengths and shallower,
more broadly distributed carapace grooves are more effective in dissipating stresses caused by impact
throughout the carapace structure. This allows them to retain stiffness for longer, and influences
their failure mode, which is ductile (denting), rather than brittle fracture. The findings in this paper
provide new bioinspired approaches for the geometrical designs by which means material failure
under cyclic impact can be controlled and manipulated. |
