Evaluation of Vertical Wall-To-Guardrail Transition

Transition barriers are used to connect longitudinal barriers that have different stiffnesses. They are designed to provide a gradual increase in stiffness towards the stiffer barrier section. In this study, a W-beam rail and a W-beam rubrail transition connecting a rigid bridge rail to a semi-rigid guardrail was evaluated using numerical and experimental methods. First, a finite element model of the transition design was constructed and validated using a 2000 kg pickup truck impact. Then, a series of vehicle models, i.e., 900 kg compact automobile, 8000 kg single unit truck and finally 30,000 kg heavy truck was used to evaluate the impact performance of the same transition design numerically. Simulation results predict that the double W-beam transition barrier performs acceptably in containing and redirecting all vehicles except 30,000 kg heavy truck. Occupant injury criteria were also found to be acceptable for all the cases, except 30,000 kg truck impact. Performing further simulations with vehicle sizes heavier than 8,000 kg that exist in crash testing guidelines is recommended to evaluate the acceptability limit of existing W-beam rail and a W-beam rubrail transition.