DESIGN AND SIMULATION OF LARGE BREAKAWAY SIGNS

Breakaway supports are common devices used for dual-support signs loca ted along the roadway. The sign system utilizes a fuse plate that is d esigned 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, wh en impacted by an errant vehicle. Two alternative designs for improvin g the wind load capacity of large dual-support signs were analyzed: a thicker fuse plate design and a balanced hinge design. The safety perf ormance of the sign systems was evaluated using nonlinear, large defor mation finite-element analysis (FEA). Crash simulation results indicat ed that both designs have the potential for meeting the safety recomme ndations set forth by the National Cooperative Highway Research Progra m (NCHRP) Report No. 350.