Low-velocity impact behaviour of biomimetic cornstalk-inspired lightweight structures

This study delves into the investigation of dynamic response and energy absorption capabilities inherent in cornstalk-inspired porous structures. The specimens were meticulously fabricated using acrylonitrile butadiene styrene (ABS), , a material chosen for its known toughness and impact resistance, through 3D printing. Characterization of the base material was conducted using Shimadzu® Universal Testing Machine and Split Hopkinson Pressure Bar. Low-velocity impact tests were subsequently executed, subjecting the structures to a dynamic strain rate of 3.04 × 10² s^-1. In-depth damage analyses were carried out using scanning electron microscopy (SEM) to understand the brittle behaviour of polymers and identify debonding in the 3D-printed layers.

The results unveiled a noteworthy 12% increase in specific energy absorption (SEA) compared with quasi-static measurements. Remarkably, the selected topology exhibited outstanding energy-absorbing capability, surpassing that of many other porous structures reported in the literature by approximately ~17.5%. Complementary numerical modeling of compressive dynamic loading was performed to reinforce our experimental findings. This research not only validates the promising potential of cornstalk-inspired structures for enhanced energy absorption but also suggests avenues for improvement through the optimization of geometrical design. Importantly, this work builds upon the author's prior exploration of the quasi-static response of the cornstalk-inspired design, providing a comprehensive and nuanced understanding of the material's dynamic behaviour.