Design and Simulation of Large Breakaway Signs

Abstract

Breakaway supports are common devices used for dual-support signs located along the roadway. The sign system utilizes a fuse plate that is designed to support the wind loads on the sign as well as to allow the sign support to release on impact, and swing up and out of the way, when impacted by an errant vehicle. Two alternative designs for improving the wind load capacity of large dual-support signs were analyzed: a thicker fuse plate design and a balanced hinge design. The safety performance of the sign systems was evaluated using nonlinear, large deformation finite-element analysis (FEA). Crash simulation results indicated that both designs have the potential for meeting the safety recommendations set forth by the National Cooperative Highway Research Program (NCHRP) Report No. 350.