Performance limit analysis for common roadside and median barriers using LS-DYNA

Abstract Performance limits of commonly used barriers in terms of acceptable vehicle impact heights were identified using non-linear finite element methodology. Finite element models for four widely used guardrail systems were developed. The selected guardrail/barrier systems are the modified G4(1S) W-beam guardrail, modified thrie-beam guardrail, Midwest guardrail system, and modified weak post W-beam guardrail. LS-DYNA simulations using these guardrail models were validated based on the results obtained from existing crash tests performed on flat terrain. To define vehicle containment limits, LS-DYNA simulations were performed with variable vehicle-to-barrier impact heights on guardrails placed on flat terrain. Override and underride limits for each guardrail model were identified using NCHRP Report 350 design vehicles. Vehicle impact height was parametrically varied to determine performance limits of each barrier as defined by initiation of override or rollover for the pickup truck and underride for the small passenger car. Keywords: guardrail performance limitLS-DYNA simulationNCHRP Report 350guardrail on slope Acknowledgements The content of this paper is the partial result of a project sponsored by the National Cooperative Highway Research Program (NCHRP). The opinions expressed in the paper are those of the authors and not necessarily those of the NCHRP. The authors wish to thank the NCHRP panel members for their inputs and help. The authors also sincerely thank the researchers at the Midwest Roadside Safety Facility, in particular Ronald K. Faller, and at the Worcester Polytechnic Institute, in particular Malcolm H. Ray, for sharing data and answering many questions. The authors acknowledge the Texas A&M Supercomputing Facility (http://sc.tamu.edu/) for providing computing resources useful in conducting the research reported in this paper. Finally, the authors wish to acknowledge the contributions made by researchers at the Texas Transportation Institute.