Integrating Bio-inspired Concepts Into Lightweight Sustainable Crashworthy Designs Under Lateral Loading Scenario

The pursuit of efficient, sustainable, and innovative solutions has sparked growing interest in bio-inspired designs across various engineering fields, drawing on the structural efficiency observed in nature. Consequently, this study investigates the crashworthiness and failure mechanisms of 3D-printed circular structures made from advanced polylactic acid (PLA +), inspired by the geometry of a horsetail. The research focuses on three critical design parameters: the inner-to-outer diameter ratio (d/D), the number of internal ribs (N), and the internal shape (IS), each varied at four levels. Crash load, energy absorption, and displacement were automatically recorded during quasi-static compression tests, and failure modes were systematically analyzed. Key crashworthiness indicators, total absorbed energy (U), specific energy absorption (SEA), and mean crash load (Fₘ), were used for performance evaluation. The findings demonstrate that increasing the number of ribs enhances energy absorption, while a higher d/D ratio generally reduces it. Notably, the CN8R (1/4) configuration, featuring a circular inner shape (C), eight internal ribs (N8), and a d/D ratio of 1/4, achieved improvements of 1042.45% in F_m, 1037.5% in U, and 495.07% in SEA compared to a baseline hollow tube. These results suggest that bio-inspired, rib-reinforced PLA + structures offer promising potential for energy-absorbing applications in automotive, aerospace, and protective packaging industries, where weight reduction, energy dissipation, and material sustainability are critical.