Energy Absorption Analysis of Circular Cross-Section Crashworthiness with Dual Gradient Under Axial and Oblique Loads

The tube structures designed in the multicell pattern are used for crashworthiness in many areas. In this study, the crashworthiness was designed by dividing the inner area of the circular section geometry into equal slices by examining previous studies. In addition, this structure was prepared as a dual gradient in two different sizes along the length. Performance parameters were investigated by performing theoretical and numerical analyses. For multicell crashworthiness, which is considered a dual gradient, the folding style was insufficient in lobe formation. However, the specific energy absorption (SEA) and the crushing force efficiency (CFE) values of the two types of dual gradient structures behaved appropriately in absorbing kinetic energy. The dual gradient new design of crashworthiness provides resistance by preventing the bending of the structure under oblique loading. According to the results of the analysis, the mean SEA and CFE under loading at all angles for the 2nd order dual gradient configuration was 12.88% and 1.61% higher than the 1st order design. However, with the preparation of circular section tubular structures using 8-panel elements, close values were obtained in the comparison of theoretical and numerical analysis under axial loading conditions.