A new homo-polygonal multi-cell structures under axial and oblique impacts; considering the effect of cell growth in crashworthiness

Abstract

In this paper, groups of new homo-polygonal multi-cell tubes are introduced and investigated under both axial and oblique loads via studying the effect of cell growth on energy absorption characteristics. Finite element models has been developed and validated by experimental tests as well as a new developed theoretical procedure for multi-cell tubes. The new developed homo-polygonal multi-cell structures are investigated considering the effect of cell growth to find the most efficient topology. Different polygonal cross-sections including pentagonal, hexagonal and octagonal are considered while each cross-section has cells in corners form that have the same shape as their own cross-section. Obtained results point out that there is a distinct connection between cell’s size and absorbed energy and cell growth could affect the energy absorption characteristics in a perceptible manner. When cells start to manifest in tubes the peak crush force increases and then drops to its original value as cells reaches their maximum possible size. Acquiring the numerical data of all the structures, by using the COPRAS multi-criteria decision-making method, the best structure is distinguished. Next, the best thickness in the best impact angle of crash found using the relevant RSM as an optimisation method.