Design of CFRP and Steel Composite Stay Cables Based on Stiffness and Economic Behavior

Abstract:

Based on the study of appropriate spans for using steel or carbon fiber reinforced polymer (CFRP) stay cables,this paper proposes a new design of CFRP and steel composite stay cables to deal with the drawback of low stiffness,especially for the cablestayed bridges with main spans of 1 400~2 800 m.More specifically,the CFRP stay cables with high strengthtoweight ratio and steel stay cables with high elastic modulus are combined together for application in cable stayed bridges,which can increase the equivalent stiffness of stay cables and then improve the entire stiffness of bridges.The design strategies for the composite cablestayed bridges are proposed in detail.Then through a parametric study concerning the equivalent stiffness and economical behavior,the proper area ratio between CFRP and steel stay cables are also proposed.Finally,the feasibility of the proposed stay cables is discussed through a case study of a cable stayed bridge with 1 400 m main span.The proposed composite stay cables demonstrate a high equivalent stiffness, which is an excellent selection for bridges with main spans of 1 400~2 800 m.