Dynamic Behavior of CFRP Hangers in a Half-Through Arch Bridge

Carbon fiber reinforced polymers (CFRP) is an ideal material for tension member, such as hangers, tied bar, stay cables in large span bridges, for its excellent properties in high strength, fatigue resistance and corrosion resistance. To study the behavior of the CFRP hangers in arch bridge, a finite element model of an as-built half-through arch bridge was established, in which the original steel hangers were replaced by CFRP ones with identical strength. The analysis of the bridge longitudinally and transversely, subjected to single-vehicle and multi-vehicle loading, is carried out. The differences between the behavior of the steel and CFRP hangers are compared. It is shown that under the vehicle loading, although the axial stress of hangers in different positions differs from each other, the variation presents in the same way. Both under single and multi-vehicle loading, the stress level of the CFRP hanger is larger than that of the original steel one, with the maximum stress value increased significantly by almost 80-100%. The axial stress distribution in the CFRP and the steel hangers is basically the same, while the frequency has different rules, of which CFRP hangers show higher. It is found that shorter hangers display larger stress both in steel and CFRP hangers, the latter presents greatly with the stress in shortest hanger higher than that in longest hanger by 51.9% on the average.