Crash analysis and dynamical behaviour of light road and rail vehicles

Abstract

The main goal of crashworthiness is to ensure that vehicles are safer for occupants, cargo and other road or rail users. The crash analysis of vehicles involves structural impact and occupant biomechanics. The traditional approaches to crashworthiness not only do not take into account the full vehicle dynamics, but also uncouple the structural impact and the occupant biomechanics in the crash study. The most common strategy is to obtain an acceleration pulse from a vehicle structural impact analysis or experimental test, very often without taking into account the effect of suspensions in its dynamics, and afterwards feed this pulse into a rigid occupant compartment that contains models of passengers. Multibody dynamics is the most common methodology to build and analyse vehicle models for occupant biomechanics, vehicle dynamics and, with ever increasing popularity, structural crash analysis. In this work, the aspects of multibody modelling relevant to road and rail vehicles and to occupant biomechanical modelling are revised. Afterwards, it is shown how multibody models of vehicles and occupants are used in crash analysis. The more traditional aspects of vehicle dynamics are then introduced in the vehicle models in order to appraise their importance in the treatment of certain types of impact scenarios for which the crash outcome is sensitive to the relative orientation and alignment between vehicles. Through applications to the crashworthiness of road and of rail vehicles, selected problems are discussed and the need for coupled models of vehicle structures, suspension subsystems and occupants is emphasized.

Keywords:

• Energy absorption
• Occupant biomechanics
• Vehicle dynamics
• Multibody dynamics
• Impact

Acknowledgements

The support of the Portuguese Foundation for Science and Technology, FCT, through project 2/2.1/TPAR/2041/95, to study the vehicle rollover is gratefully acknowledged. The support of EC through projects BE-96-3092 (SAFETRAIN), with the partners ADTRANZ/SOREFAME (Pt), ERRI (Nl), SNCF (Fr), DB (Ge), PKP (Pl), FMH (Pt), CIC (UK), GEC/MC (UK), AEA Technology/BRR (UK), U. Valencienne (Fr), GAC/CIMT (Fr), ALS/DDF (Fr), IFS (Ge), TU Dresden (Ge), DUE (Ge), enabled to develop the studies on train crashworthiness and through project TIP3-CT-2004-506503 (APROSYS-SP6), with the partners SIEMENS VDO (Ge), Faurecia (Ge), DaimlerChrysler (Ge), CIDAUT (Sp), Fh G (Ge), Warsaw University of Technology (Pl) and TNO (Nl) provided the results of the road vehicle side impact studies. The EC support is also greatly appreciated.