Crashworthiness analysis of gradient hierarchical multicellular columns evolved from the spatial folding

• A gradient hierarchical multicellular column evolved from the spatial folding is proposed. • Its specific energy absorption can increase by 27% to 98% compared with the square tube. • Novel columns with smaller height and larger wall thickness tend to form the compact mode with better performances. • Simplified super folding element theory can be used to predict its mean crush force with high accuracy. Based on the gradient hierarchical distribution of vascular bundles of bamboo, a gradient hierarchical multicellular column (GHMC) evolved from the spatial folding was proposed. Crashworthiness analysis of GHMC was carried via Abaqus/Explicit. Results show that the proposed GHMC has better energy absorption ability compared with the square tube under the same thickness or the same mass. The folding wavelength of GHMC is significantly decreased and it can produce more number of folds compared with the square tube. Under the condition of the same mass, the peak crushing force of GHMC decreases meanwhile its energy absorption increase by 10.1% to 72.44% compared with the square tube. Effect of hierarchical level and cell wall thickness on the energy absorption and their deformation mode under different height-length ratio ( H / L ) and cell wall thickness have been analyzed. Simplified super folding element theory was used to predict the mean crush force of GHMC, and the results were in good agreement with the simulations.