Finite element simulations of high-frequency crash signals for robust crash discrimination

Abstract

This work presents finite element simulations of a crash-management system and a body-in-white vehicle structure under low-speed crash conditions. The simulation models can be used to predict the excitation of high-frequency acceleration signals due to the initial impact and deformation of the crash-management system. In recent years, modern crash detection systems started to use frequency crash signals up to 20 kHz to distinguish between different crash severity levels and to trigger the restraint systems accordingly. The parameterization and application of such crash detection systems to new vehicle models require extensive testing of vehicle prototypes. The discussed approach allows assessment of the virtual components with respect to the signal quality at an early design stage. The first part of the study covers a ball-drop test to identify and isolate relevant modelling parameters. The second part discusses a crash-management system model and a low-speed crash with a body-in-white vehicle structure. Although finite element method crash simulations have already become a standard tool for assessment of the vehicle safety, no published work was found on the excitation of crash signals in that particular frequency range. The results show that the present-day finite element method is already capable of simulating frequency signals up to 20 kHz, which are excited through complex deformation processes. The simulation results are validated by experimental data and are within the measuring accuracy and the experimental repeatability. Simulations of crash signals allow simultaneous design optimization of the vehicle components and the crash detection system.

Multi-objective optimization of a novel crash box with a three-dimensional negative Poisson’s ratio inner core

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