A novel multi-cell square tubal structure based on Voronoi tessellation for enhanced crashworthiness

Abstract

Abstract In this paper, a novel multi-cell tubal structure with randomized cell sizes is proposed to enhance the energy absorption of the conventional square tubes by utilizing the random nature of Voronoi tessellations. Experiments were conducted to develop and validate finite element models. The crashworthiness of these tubes was demonstrated by applying axial and bending loads using the finite element method. The proposed multi-cell tubal structures exhibit a progressive and stable deformation with the formation of folds in the axial loading case and a local and global deformation for the lateral bending case. The peak crushing force (PCF) and specific energy absorption (SEA) of the proposed multi-cell tubal structures were found to be better than the regular multi-cell square tubes with equal cell sizes when subjected to axial loads. When subjected to lateral bending load, the proposed multi-cell tubal structures have a better PCF while the regular multi-cell square tubes have a better SEA. An optimization problem was formulated to enhance the crashworthiness of the structures. The objective functions were derived using meta-models to speed off the search for optimal structures. The axial crushing and lateral bending cases were optimized separately and combined. Multi-objective particle swarm optimization (MOPSO) was employed to solve the optimization problems. The optimal tubal structures have a crushing efficiency of 87.1% and 85.6% for axial and bending loads, respectively.