On folding mechanics of multi-cell thin-walled square tubes

Multi-cell metallic thin-walled tubes have gained wide popular in recent years, due to their significantly improvements in mechanical behaviors comparing with general single sample. In this investigation, some attempts to learn of the mechanism of folding process of multi-cell thin-walled square tubes were carried out. The half-wave length has been fully determined theoretically by the means of Super Folding Element. The relationship between the half-wave length as well as mean load versus cell amounts has been given. Afterwards, comprehensive numerical simulations were also conducted after necessary experimental validation, with the cell amounts range from 1 × 1 to 15 × 15 which have the equal weight but different thickness. Detailed evolutional process of deformation mode, half-wave length, and energy absorption capability were analyzed parametrically. The results turned out that the vital influence factor on mechanical properties of multi-cell tubes directly lies in the half-wave length caused by different cell amounts. With the increasing of cells, the half-wave length decreases while the energy absorption capability promotes. Evidently promotion can be observed compared with general single cell tube. All these achievements shed a light on disclosing the multi-cell effect on mechanical properties.