Low velocity impact and compression after impact of thin-ply CFRP Bouligand structures

In this work, several bio-inspired thin-ply CFRP laminates mimicking the helicoidal architecture of the mantis shrimp's dactyl club periodic region have been modelled and tested under low velocity impact (LVI) and compression after impact (CAI), investigating the effect of the inter-ply angle (pitch angle) on the mechanical response and damage characterization of the biomimetic laminate. The use of thinply technology has allowed for the first time to explore the effect of very small inter-ply angles, down to 2.5°, better mimicking the microstructure of the dactyl club and achieving failure mechanisms akin those observed in the natural microstructure. Tests conducted for a wide range of pitch angles (2.5°, 5°, 10°, 20°, 45°) show that, by decreasing the pitch angle, is it possible to better mimic the failure mechanisms observed in the biological microstructure