Evaluation of the vehicle/safety barrier/fixed object interaction by means of FEM simulations

Within a large research project a set of Finite Element Models of the full vehicle/safety barrier/fixed object systems has been developed in LS-DYNA environment with different barrier models validated according to the most recent validation procedures and with different type of fixed objects. This paper is focused on the evaluation of the interaction of a specific barrier with a Variable Message Sign (VMS) that is a critical structure as it is often placed very close to the roadway to reduce the length of the arm above the carriageway. The two issues addressed in the paper are the structural response of the VMS, in order to ensure that the structure will not fail under the impact of an Heavy Goods Vehicle (HGV), and the effects of the secondary impact with the structure in terms both of overall performance of the barrier and of the resulting effects on the HGV itself. As a results the minimum distance between the front of the barrier and the VMS support structure that will enable to have a performance of the system fully compatible with the requirements of EN1317-2 has been defined for the specific barrier analysed. The results obtained allow to conclude that the developed procedure can be extended to the evaluation of any vehicle/safety barrier/fixed object combination.