Effect of Vehicle Roof Shape on Rollover Safety

Most rollover safety research considers the vehicle in an inverted (upside-down) position as the major cause of serious injuries. For example, neck injuries mostly occur when the vehicle roof strikes the ground. However, recent studies have identified that significant injuries can occur to restrained and contained occupants during other phases of the rollover event, including when the vehicle is on its side and upright. Some injurious impacts between the occupant and vehicle interior such as torso injuries are likely related to changes in their relative velocities (Δv). Such velocity changes are believed to be associated with a higher number of quarter turns during a rollover event._x000D_
_x000D_This study seeks to identify the role of roof shape for Sports Utility Vehicles (SUVs) in the potential for exacerbating vehicle-occupant Δv and thus the potential risk for associated occupant injuries. Detailed computer finite element model (FEM) rollover crash analysis, determining the kinetic energy, translational velocity and roll rate changes of a simplified proxy SUV FEM vehicle that occur during a two roll event for two vehicle roof shapes (square and rounded), is presented. The vehicle’s kinetic energy, translational velocity and roll rate for each considered roof shape during the rollover are compared. It is hypothesised that the rounder roof design results in a less severe change for each of these variables particularly towards the end of the rollover event, thereby reducing occupant-vehicle impact severity. This work is part of an ongoing study needing further work to confirm these findings in real-world SUV rollovers._x000D_