Crashworthiness enhancement of thin-walled hexagonal tubes under flexural loads by using different stiffener geometries

Abstract

Thin-walled structure tubes have been widely used in automotive applications as energy absorber members due to the excellent energy absorption ratio to the weights. The purpose of this study is to enhance the energy absorption of the thin-walled hexagonal tube by using different stiffeners geometries under the flexural impact. The structure has been subjected to an impact velocity of 50 km/h with a striker mass of 1500 kg at a 90-degree angle as recommended by the technical protocol section of the Insurance Institute for Highway Safety (IIHS) side-impact crash test. Besides the empty tube and the foam-filled tube, nineteen stiffeners were used in this study. A comparison between the reinforced and non-reinforced structure was made in terms of the specific energy absorption (SEA) and the crushing force efficiency (CFE). The numerical results have shown that stiffeners have improved the crashworthiness parameters when compared with the conventional empty tube. The numerical results have revealed that the introducing stiffeners to the structure have enhanced the structure performance since the stiffeners restrict the flattening of the upper side when subjected to compressive loadings and the SEA was improved for different wall thickness used. The results have shown that the H-5 stiffener was chosen as the best geometry since the SEA was increased up to 114%, the CFE was enhanced by 27% and the bending resistance was also improved.