Crushing analysis of thin-walled beams with various section geometries under lateral impact

• Bending property of beams with various sections was investigated.
• Elliptical sectional beam had better bending property than its counterparts.
• Sectional dimensions along impact direction greatly affected the bending property.
• New beams were constructed by combination or adding ribs.
• The strengthening effects of these new beams were investigated.

Due to the advantages of light weight and excellent energy absorption capacity, thin-walled beams are widely used as strengthen parts or energy absorbers in vehicle body. Thus, the collapse behaviors and mechanical properties of thin-walled beams under the static and dynamic loadings have drawn great attentions of the researchers. In vehicle side crash accident, the contact parts of the vehicle usually deformed in bending mode. Thus, it is significantly important to investigate the bending collapse behaviors of these parts. In this study, the bending behaviors of several thin-walled beams with simple cross section subjected to lateral impact were investigated using analytical and numerical methods. The crashworthiness parameters such as energy absorption (EA), average crash force (Favg), peak crash force (Fmax) and crash force efficiency (CFE) were employed to evaluate the bending resistant property. In order to study how geometry shapes affect the bending performance, the main geometry parameters such as radius/radius ratio of circular/ elliptical section, side length ratio of rectangular section, height and base angle of hat section were chosen as the design parameters. After investigating the beams with simple cross sections, some new beams with complex cross sections were constructed by combing these simple beams or adding reinforce ribs to these simple beams. Then, the bending performance of these new beams was studied by numerical simulation and compared with original section beams. Result shows that the section type b performs better in SEA and CFE than original simple section beams. It also can be concluded that adding ribs can greatly improve the bending resistant performance for circular, rectangular and hat section beams, and the vertical ribs can achieve the best reinforce effect for the circular and rectangular section beams.