Improvements to G4(RW) Strong-Post Round-Wood, W-Beam Guardrail System
Publication: Journal of Transportation Engineering
Volume 131, Issue 1
Abstract
Strong-post round-wood W-beam guardrail, G4(RW), is a common longitudinal barrier used in Texas. Recent crash tests on the system demonstrate its effectiveness in containing and redirecting a pickup truck. Even though the guardrail performed satisfactorily according to National Cooperative Highway Research Program Report 350 requirements, there were concerns about the stability of the vehicle due to excessive wheel snagging on the posts. In this study, a modification to the existing design is evaluated to improve the stability of an impacting vehicle. LS-DYNA, a dynamic, nonlinear, large deformation finite element modeling code is used to analyze and compare the performance of alternate designs. A baseline finite element model of the existing system is developed to replicate the observed crash test behavior of the G4(RW). The fidelity of the baseline model is verified against full-scale crash test results. To improve the vehicle stability, the current design was modified to include guardrail posts with shorter embedment depth. An optimum post embedment depth was determined and used in the second simulation study. Finite element analysis results show that an improved G4(RW) system eliminates wheel snagging on posts, reduces sudden vehicle deceleration and therefore improves the stability of an impacting vehicle significantly.
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Acknowledgments
The writers greatly acknowledge Dr. Malcolm Ray and Dr. Chuck Plaxico, researchers at Worcester Polytechnic Institute, for their help on finite element models of the G4(RW) guardrail system, and Dr. Hayes E. Ross, Jr., Dr. Roger P. Bligh, and Dr. Akram Abu-Odeh for providing assistance with the study.
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Information & Authors
Information
Published In
Journal of Transportation Engineering
Volume 131 • Issue 1 • January 2005
Pages: 63 - 73
Copyright
© 2005 ASCE.
History
Received: Sep 10, 2002
Accepted: Nov 4, 2003
Published online: Jan 1, 2005
Published in print: Jan 2005
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