Development of a new lumped-parameter model for vehicle side-impact safety simulation

The current paper describes a simple and yet comprehensive lumped-parameter model (LPM) for simulating the National Highway Traffic Safety Administration (NHTSA) side-impact safety tests for passenger vehicles. The LPM includes new lumped masses, not previously reported in a single multibody model, for key vehicle side-structure systems identified with the help of an energy-based study conducted using explicit finite element analysis of two passenger vehicles. In addition to the vehicle side structure, lumped masses for the NHTSA side-impact barrier and 'rest of vehicle', the latter implying the mass of the vehicle minus the combined mass of the side-structure subsystems considered in the LPM, have been incorporated so that the total mass of the system corresponds to that of an actual vehicle-barrier system in a NHTSA side-impact test (Lateral Impact New Car Assessment Program (LINCAP) or FMVSS 214). The lumped masses are interconnected with elastic-plastic springs. A unique feature of the present model is the inclusion of two lumped side-impact dummies for obtaining predictions of the front and rear (thoracic trauma index (TTI)). The validity of the present LPM is established by performing LS-DYNA-based LINCAP simulations of two real-world vehicles, namely the Dodge Neon and Dodge Intrepid, and obtaining a reasonably good correlation of the computed structural and occupant responses as well as TTI (front and rear) with the corresponding test results reported by the NHTSA.