Study of the aerodynamic damping of wing plates on traffic signal structures based on the 2D one-way FSI analysis

ABSTRACT

To improve the fatigue performance of these traffic signs, luminaries and signals structures, the wing plate, a type of aerodynamic damper, is adopted to control the dynamic responses due to wind-induced fatigue load. In this study, one-way 2D fluid-structure interaction (FSI) analysis is conducted to investigate the mitigation ability of the wing plate. Parametric study is involved to investigate the influence on the damping effect caused by the different configuration of the wing plate, as well as the wind speed. The different configurations of signals and signs applied in Maryland, USA, have been studied to find the potential aerodynamic instability due to galloping. The required length of wing plate for the 23-m mast-arm signal structure in Maryland have been analyzed. The study shows that small space between the wing plate and the arm will reduce the mitigation ability. Wing plate may lose mitigation ability due to stalling. Large vortex shedding is observed in the FSI analysis. The wing plate with dimension 610 mm × 610 mm applied by PennDOT can effectively prevent galloping for signal pole structures in Maryland. This research can be used as a reference for the selection of mitigation devices to satisfy the “effective mitigation devices” stated by AASHTO.

KEYWORDS:

• Mast-arm traffic signal structures
• wind-induced fatigue load
• galloping
• wing plate
• aerodynamic damping
• CFD simulation
• fluid-structure interaction (FSI)

Acknowledgments

Authors gratefully acknowledge the funding support received from the Maryland State Highway Administration (MDSHA) through FHWA/SPR (Sponsor contract number: SP609B4F) titled “Fatigue Resistant Design Criteria for MD SHA Cantilevered Mast Arm Signal Structures.”

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Maryland State Highway Administration; Maryland State Highway Administration [SP609B4F]; Maryland State Highway Administration; Maryland State Highway Administration; Maryland State Highway Administration.