Improving the Roadside Safety with Computational Simulations

Matej Vesenjak, Zoran Ren University of Maribor, Faculty of Mechanical Engineering, Slovenia The road restraint systems on public streets are used to prevent a vehicle to veer off the road or its breakthrough to the opposite side of the road. The road restraint systems designed according to the EN 1317 standard are intended to provide certifiable levels of vehicle containment, to redirect errant vehicles and to provide guidance for pedestrians and other road users. Its proper design is therefore crucially important for safety of all road users. Practical observations of installed systems indicate that the current design of road restraint system is far too stiff. This results in unacceptable decelerations during the vehicle impact. The global stiffness of the road restraint system is largely attributed to the design of the distance spacer in the initial phase of an impact. The purpose of this research is to evaluate several new designs of a distance spacer with increased strain energy absorption due to controlled deformation during the vehicle impact. The impact severity and stiffness of various designs have been evaluated with dynamic nonlinear elasto-plastic analysis of a three-dimensional road restraint system within the framework of the finite element method with LS-DYNA. The computational analyses prove that the currently used distance spacer is indeed too stiff and that new designs assure controllable elasto-plastic deformation and crash energy absorption which in turn decreases the decelerations of an impact vehicle and consequently increases the safety of vehicle passengers.