Perpustakaan Digital ITB

To fulfil the high mobility of modern society without compromising environmental aspects, research and development for a low emission public transportation needs to be implemented, electric bus for example. But unfortunately, the battery pack used as a power source in electric vehicles are still susceptible to failure due to fire or even explosion if subjected to a high load and deformation. Since statistically, the rate of fatality caused by frontal crash impact is still significantly high, a crashworthiness structural design that is able to absorb most of the crash impact energy is needed. This crashworthiness design is used not only to guarantee the safety of the battery pack, but also the safety of the occupants. Taking advantage of today’s technology of lightweight metals and extrusion manufacturing, engineers use an aluminium extrusion based thin-walled columns as an energy absorber. In this research, two types of columns are studied using non-linear finite element method, namely single cell and multi-cell columns with various configurations. The objective of this research is to design and find out what type of multi-cell cross sectional geometry is most adequate to use and also comply to safety regulation for frontal crash (FMVSS No. 208). The numerical simulations were done using the assumptions that the frontal impact load is axially loaded to the bumper and crash boxes. The results of each design and configuration are analysed based on their crashworthiness performance. It is concluded that the use of multi-cell with a cruciform configuration can increase the energy absorbing ability up to 71% compared to the use of single cell. Indentation triggers are used in the multi-cell columns to prevent global buckling. It is also concluded that to achieve an optimum energy absorbing design, not only do the thickness and the number of corners need to be optimized, it is also important that a stable and progressive collapse pattern is maintained throughout the column.