Crash analysis of foam and concrete filled automatic retractable bollard under vehicle impact

摘要

Vehicular borne attack is one of the most recent means of threats to civilian and defense infrastructures. To counter such vehicle borne attacks, automatic retractable bollards proves to be effective. In the present investigation, numerical analysis of an automatic retractable bollard is carried out using LS-DYNA®. A comprehensive nonlinear finite element model is developed to test simulate the performance of foam and concrete filled automatic retractable bollard under K4, K8 and K12 ratings. Numerical investigation shows that both the impact force and bollard deflection increase with the increase in truck impact speed and foam/concrete filling enhances the performance of bollards considerably. Based on numerical simulation, it is observed that at relatively high speed truck has a tendency to climb over the bollard despite severe damage to the truck front. Further, it is observed that impact force varies along the bollard height and it is not uniform during the impact process.