Bending Characteristics of Folded Multi-celled Tubes with Square and Circular Section Geometries

This research investigates the bending response of folded multi-celled tubes (FMTs) fabricated by folded metal sheets. A three-point bending test for FMTs with circular and square sections is designed and introduced. The base numerical models are correlated with physical experiments and a static crashworthiness analysis of six FMT configurations to assess their energy absorption characteristics. The influences of thickness, sectional shape, and load direction on the bending response are studied. Results indicate that increasing the thickness of the tube and radian of the inner tube enhances the crashworthiness performance of FMT, yielding a 20.50% increase in mean crushing force, a 55.53% increase in specific energy absorption, and an 18.05% decrease in peak crushing force compared to traditional multi-celled tubes (TMTs). A theoretical analysis of the specific energy absorption indicates that FMTs outperform TMTs, particularly when the peak crushing force is prominent. This study highlights the innovative and practical potential of FMTs to improve the crashworthiness of thin-walled structures.