Development of finite element model for the analysis of a guardrail post subjected to dynamic lateral loading

Abstract

The performance of a guardrail system depends on many factors where the interaction between the soil and the post plays a major role in the vehicle response. In this study, a computer simulation model of a rigid impactor impacting a roadside post has been developed and the interaction of cohesionless soil with a W152 × 13.4 post was studied and compared to the existing dynamic test results from the published literature. Two approaches have been studied: the continuum method where the soil was modelled as a solid element with Drucker and Prager material law and an upgraded subgrade approach where the soil was modelled as a system of parallel springs and dampers with a lumped mass attached to the post. The results of the new subgrade method and the continuum method were compared to the dynamic test. The new method shows very close results to the dynamic tests.