摘要: |
This report summarizes the research efforts of using finite element modeling and simulations to evaluate the performance of NCDOT W-beam guardrails behind curbs under MASH TL-2 impact conditions. A literature review is included on performance evaluation of W-beam guardrails as well as applications of finite element modeling and simulations in roadside safety research. The modeling and simulation work was conducted on three NCDOT W-beam guardrails (with placement heights of 27, 29, and 31 inches) placed at the curb face and at 12 feet from the curb face. The 29-inch guardrail was also evaluated at 6 feet from the curb face. The guardrails with 27-, 29-, and 31-inch placement heights were impacted by a 1996 Dodge Neon and a 2006 Ford F250 at 44 mph (70 km/hour) and at two impact angles (25 degree and 15 degree). The guardrails performance was determined by evaluating the vehicular responses based on MASH exit box criterion, MASH evaluation criterion F, exit angles, yaw, pitch, and roll angles, transverse displacements, and transverse velocities. The simulation results demonstrated the effectiveness of the 29- and 31-inch guardrails placed at 12 feet from the curb face under MASH TL-2 impact conditions. Under small angle vehicular impacts (i.e., 15 degree), the guardrails with 27-, 29-, and 31-inch placement heights were shown to be effective at all three placement locations in relation to the curb face. Finite element modeling and simulations were shown to be both effective and efficient and can be used to study crash scenarios that are difficult and/or extremely expensive to conduct with physical crash testing. |