Quasi-static study of thin aluminium frusta with linearly varying wall-thickness

摘要

Energy absorbing structures are very important for safety reasons in automotive industries. Large portion of energy absorption depends on plastic deformation. Metallic frusta are extensively studied as plastic deformable energy absorbers. In this study, the experimental as well as numerical simulation are presented for metallic frusta with linearly varying wall thickness. Specimens are prepared from 6063 extruded solid aluminium shaft, annealed and tested under quasi-static compression. Two semi-apical angles viz. 5 degrees and 10 degrees along with thickness variation manner, resulting in four configurations of frusta are tested and analysed. Increasing the semi-apical angle increases the deformed mass efficiency within the studied range of angles. This also increases the compactness of the deformed material that leads to slight improvement of the specific energy absorption. Simulations are performed using Abaqus 6.14 commercial software. S4, S4R, C3D8R elements are used for modelling the frusta. Detailed analysis is done and results are presented. Among them the element S4R exhibits best simulation features. The simulation results are compared with the experimental results, and both are in good agreement. The best agreement between them is found to be when the frustum diverging and the thinning slope collaborate to initiate the collapse from the same side.