Assessment of the robustness of vehicle restraint systems crash tests by numerical simulation and consequences on the regulation v2

Abstract

Road safety structures are CE-marked products. The declared performances are obtained during crash tests defined within EN1317. These crash tests are performed using second-hand vehicles which only need to fulfil very few requirements (mainly global dimensions and total mass). As a consequence, the vehicles used in different test laboratories differ from one another. Numerical simulation has been widely used for several decades to assist in the design of new road safety devices. The above-mentioned variability of the vehicles affects the reliability of the simulations, leading to discrepancies between models and real tests results. Indeed, vehicle restraint systems performances may be different depending on the vehicle used for the crash test. In a first part, this paper presents correlations between tests and numerical simulations using LS-DYNA software, on various vehicle restraint systems made of different materials (steel, steel-wood, concrete…) and of various restraint levels, in order to show the capability of the models to represent the experiments. In a second part, the vehicles models are modified, while still respecting the EN1317 requirements, and the corresponding impacts on the products performances are evaluated. Finally, some simulations with impactor models are presented as a proposal to reduce the variability of the crash tests and then increase the reliability of the CE marking.