Investigation of combined effects of cross section, taper angle and cell structure on crashworthiness of multi-cell thin-walled tubes

Crash box design has a substantial importance to reduce the fatalities in a frontal crash. In this study, four different types of multi-cell tubes, namely straight-circular, straight-square, tapered-circular and tapered-square geometries, are considered as energy absorbing components. For each type, seven different cell structures are designed, and the crashworthiness of these designs is assessed based on two different metrics: crush force efficiency (CFE) and specific energy absorption (SEA). When the thickness and the taper angle are fixed, the multi-cell design having the best performance is found to have 165% larger CFE and 237% larger SEA compared to the single-cell design having the worst performance. By varying the thickness, the CFE and SEA performances of the best design can be further increased by 5% and 7%, respectively. Similarly, by varying the taper angle, the SEA performances of the best design with varied thickness can further be increased by 4%.