Torsional Behavior and Fatigue Assessment of H-shaped Arch Bridge Hanger by Wind-induced Vibration

H-shaped hanger in arch bridge due to its high slenderness ratio and low torsional stiffness is prone to wind-induced torsional motion under low wind speed, thus leading to the fatigue problem at the flange of hanger near the hanger-to-beam connection. The available data is relatively limited to evaluate the fatigue behavior under torsional response of the H-shaped hanger. To assess the impact of this behavior on the service life of the H-shaped arch bridge hanger, a finite element analysis and analytical investigation were undertaken based on the practical engineering of Dongping Bridge. The results obtained from the finite element analysis correlated well with analytical methods. The calculation showed that the fatigue life of the hanger was reduced with the increase of torsion angle. It was determined the angle range for the No.1 hanger of Dongping Bridge without fatigue failure. The torsion angle can be used as the design target of vibration control.