Failure and energy absorption of plastic and composite chiral honeycombs

This paper investigates the crushing response of honeycombs having a chiral geometry, a non centre-symmetric topology made of circular cylinders connected by ligaments. Buckling and post-buckling responses of flatwise compressed plastic chiral honeycombs are numerically investigated. Results indicate that plastic chiral honeycombs can carry increasing loads beyond local buckling of ligaments, though the post-buckling response does not lead to high energy absorption performances. The characteristics of chiral topology can be exploited by adopting composite materials. The composite units produced by using a specific technological process presented in the paper and endowed with a bevel trigger failed by progressive crushing and obtained promising specific energy absorption levels.