Paper Title
Design Optimisation and Fea of Thin-Walled Aluminium Foam Filled Crashbox

Abstract
The objective of this work is to design and optimise a crashbox with foam to enhance the energy absorption capability with a lesser initial peak force and deformation, thereby facilitating its effectiveness in vehicle bumper system. In order to achieve this, a finite element analysis is conducted using LS DYNA software and the crashworthiness parameters are calculated. The modelling of the crashbox, bumper beam and fascia are done using NX 11 and meshing process is carried out in HYPERMESH. All the simulations and post processing are done using LS DYNA software. Initially, plane crashboxes made of aluminium alloy 6060 T4 for four different cross sections with the same length, perimeter and thickness are subjected to axial loading and their crashworthiness parameters are compared to select the best cross section. The thickness optimisation is carried out for this selected cross section of the crashbox. This crashbox with optimised cross section and thickness is considered as the base model. For further optimization, the mass, length, and perimeter are considered same as that of the base model and effect of different corrugation configurations are investigated which gave an advantage of lower initial peak force with higher crushing force efficiency. Based on the comparison of crashworthiness parameters, an optimum corrugation configuration is selected. Further, the effect of using an aluminium foam as a filler is analysed which showed significant improvement in the energy absorption capability and other crashworthiness parameters. The crashworthiness parameters of this corrugated crashbox with foam is found more effective with lower initial peak force when compared to that of empty corrugated crashbox of increased thickness and same mass. Finally, the base model crashbox and the optimised corrugated crashbox with foam are integrated to the bumper system separately and for both,frontal impact analysis is carried out in line with EURO NCAP standard. The results showed that the energy absorption in the bumper system with the optimised corrugated foam filled crashbox significantly improved in comparison with the base model, suggesting the use of corrugated foam filled crashbox for enhanced crashworthiness of the vehicle bumper system thereby improving the safety of occupants and vehicle. Keywords - Foam, Energy Absorption, Crashworthiness, Mass, Corrugation