Tests and simulation of a w-beam rail-to-post connection

Abstract

The bolted connection of a w-beam rail to a guardrail post can have a significant affect on the performance of a guardrail system. For example, if the connections are too strong, the w-beam is likely to be pulled to the ground with the post and result in the vehicle overriding the guardrail. If the connections are too weak, the rail can pull away from the posts too soon allowing the rail to drop and the vehicle to penetrate behind the system. In recent years, finite element simulation has rapidly become a fundamental part of the analysis and design of roadside safety hardware systems, and as such, the finite element models must be capable of accurately simulating the response of these bolted connections. One of the challenges of simulating guardrail collisions is obtaining accurate models of each of the distinct components of the system, such as the various types of bolted connections, and properly modelling their interaction with each other. This study investigates the failure mechanism of the bolted connection of a w-beam rail to a guardrail post using laboratory experiments and uses that information to develop computationally efficient and accurate finite element models of the rail-to-post connection that can be used in routine analysis of guardrail system performance using LS-DYNA.