Energy absorption of thin-walled multi-cell tubes with DNA-inspired helical ribs under quasi-static axial loading

Abstract

This study presents a pioneering investigation into the energy absorption characteristics of thin-walled multi-cell tubes with DNA-like helical ribs under axial loading, marking the first such exploration in the literature. By systematically varying key design parameters—inner diameter, number of spirals, and spiral turns—we aimed to optimize the energy absorption performance of these complex structures. A total of 27 geometrically intricate multi-cell tubes were fabricated using fused deposition modeling (FDM) and subjected to rigorous axial compression tests. Crashworthiness metrics, including energy absorption, specific energy absorption (SEA), mean crash force (MCF), peak crash force, and crash force efficiency (CFE), were meticulously analyzed. Signal-to-noise ratio analysis and ANOVA were employed to discern the influence of design factors on these metrics. The findings revealed that the number of spirals significantly dictates the energy absorption capacity, with inner diameter exerting the least influence. Specifically, the inner diameter, spiral number, and spiral turns contributed 0.96%, 71.69%, and 17.69% to MCF; 13.03%, 59.22%, and 13.17% to SEA; and 0.13%, 47.39%, and 13.11% to CFE, respectively. Notably, the optimal selection of spiral and inner diameter parameters enhanced the SEA and CFE of the tubes by up to 166.62% and 169.70%, respectively. These results underscore the critical role of helical design in augmenting the crashworthiness of thin-walled multi-cell structures.