Abstract
Keywords
Rollover, Crash Tests, Accident Analyses, Numerical simulation, SUV
Abstract
Previous improvements concerned with secondary vehicle safety have principally been directed towards reducing impact against the front or side of the vehicle. Meanwhile the modus operandi has changed and the general approach of the accident research and the automotive industry is now to be concerned with the safety of the vehicle as a whole. This includes as part of the primary safety an active rollover accident prevention and enhanced occupant protection in rollover cases as a contribution to secondary safety. Especially in the context of US-American accident occurrence the rollover is a type of accident which results in many fatalities, especially in the case of SUVs, vans and pickups. In view of recent trends in changes of the vehicle fleet mix this could become an important consideration for Europe, too.
Restraint systems already in common use such as safety belts, belt pretensioners and side airbags (curtains) do have the potential to reduce the risk of occupants being injured during a rollover crash. Other special rollover-protection systems are in the stage of development and testing. In order to calibrate the trigger algorithms and assess the structural performance of a vehicle, several rollover crash tests are required and they need to mirror the real-world accident occurrence. At present there are two tests prescribed by regulation for the US market, FMVSS 208 which describes a rollover crash test around the longitudinal axis of the vehicle and FMVSS 216 which describes a static load at the edge of the roof between the front A-pillar and the central B-pillar. There are no procedures prescribed by regulation for the European market.
DEKRA carried out an evaluation of the real-world rollover occurrence based on national and international statistics and publications as an analysis of their own accident database. This supplements the knowledge already required about these accidents in the crash and pre-crash phase and the rollover itself. A rollover test matrix is in use for full-scale hardware tests: the corkscrew rollover test, the curb-trip rollover test, the embankment test and the sandpit rollover test. In the preliminary stages of these crash tests a numerical simulation can supply very important information, for example about the boundary between the roll and the no-roll and the no-roll event.
The article gives an overview of real-world accident statistics and relevant scenarios as well as tests and their use in studying the performance of algorithms to activate protection systems under different roll and no roll conditions.