Influence of Mass Distribution of Battery and Occupant on Crash Response of Small Lightweight Electric Vehicle

Small lightweight electric vehicle (SLEV) is an approach for compensating low energy density of the current battery. However, small lightweight vehicle presents technical challenges to crash safety design. One issue is that mass of battery pack and occupants is a significant portion of vehicle's total weight, and therefore, the mass distribution has great influence on crash response. This paper presents a parametric analysis using finite element modeling. We first build LS-DYNA model of a two-seater SLEV with curb weight of 600 kg. The model has no complex components and can provide reasonable crash pulses under full frontal rigid barrier crash loading and offset deformable barrier (ODB) crash loading. For given mass of battery pack and one occupant (the driver), different battery layouts, representing different combinations of center of gravity and moment of inertia of the whole vehicle, are analyzed for their influences on the crash responses under the two frontal crash loadings. Then the mass of a second occupant is added to the passenger side for analysis. It has been found that these changes of mass distribution have significant impact on the crash pulse shape and peak, through the pitch in the full frontal crash loading and the yaw in the ODB loading. Therefore, mass distribution is critical in crash safety design of SLEV.