Design and manufacturing of energy absorbing metallic and composite crash-box

In this study, the deformation behavior and energy absorption capability of the circular aluminum tubes (6063-T5) reinforced internally and externally and annular-rolled were investigated experimentally. PVC foams with different densities were used for inner reinforcements and glass and carbon fiber were used for reinforcing the tubes from the outside. In the annular-rolling process, instead of the reinforcing element, the tube wall is locally deformed. In the experiments, firstly, the deformation behavior of the base tube under axial load was examined in detail and it was found that the tube structure deformed in different folding modes according to the geometrical dimensions, regardless of the mechanical properties. In addition, the increase in wall thickness has a more dominant effect on the absorbed energy than the increase in diameter. In the internal reinforcement, PVC foams having different densities were used in different sequence combinations in the direction of the tube length. It was found that the energy increase is due to the axial resistance of the foam and the interaction between the tube wall and the foam, in order to make this interaction clearer, low and high-density foams are used in varying radial direction. As a result of the experiments, it was found that radial foam reinforcement increased the energy value by approximately 48% and when SEM images of reinforced samples were examined, it was found that the compression of the foam between the folded tube walls was effective in this energy increase. It was found that in the case of external reinforcement, the first peak force is increased independently of the fiber type, and the fibers contribute to the wall stability of the tube, in particular. It was also found that the carbon fiber reinforcement is less brittle than the glass fiber and acts more harmoniously with the folding tube wall. It was seen from the annular-rolled specimens that the folding, which starts normally near the upper or lower ends of the tube, can be directed to the middle parts of the tube and the absorbed energy value has been increased by 26%. Since no reinforcing elements are used, this value is also equal to the specific energy absorption value of the tube. When the most efficient case was used together in each reinforcement method, the absorbed energy value increased by 2,4 times compared to the base tube and reached 4381 J level and the specific energy value increased by 37%