AUTHOR COPY Bridge Structures 10 (2014) 129–143 DOI:10.3233/BRS-150082 IOS Press 129 Optimization of the economic practicability of fiber-reinforced polymer (FRP) cable-stayed bridge decks Rajai Al-Rousan ∗ , Rami H. Haddad and Mutaz A. Al Hijaj Department of Civil Engineering, Jordan University of Science and Technology, Irbid, Jordan Abstract. This paper aims to find the optimum cable spacing and the optimum FRP deck stiffness in terms of vertical deformation. To achieve the objective of this study eighteen models are developed using ABAQUS; three different deck stiffness and six different cable spacing. Firstly, a non linear static finite-element analysis is performed on the models; then pre-tensioning forces are applied to cables, after that the shape modes for each model are presented. Secondly, a nonlinear dynamic analysis is performed on the models, the results obtained from the finite-element analysis are used in the optimization. The results show that for certain cable spacing the deflection decreased, and the cable stress increased as the deck stiffness increased. Furthermore, for certain deck stiffness, the cable stresses and the maximum deck deflection increased as the spacing between cables increased. Secondary, a relationship is performed to find the optimum cable spacing for each deck stiffness and optimum deck stiffness for each cable spacing. Finally, new twelve models are developed in order to study the effect of deck types (FRP, Concrete and steel) on the static and dynamic behavior. The results show that the using FRP deck instead of the concrete deck will lead to vertical deformation and cable stress less than the allowable proposed values by the design code because of the light weight of the FRP materials. Keywords: Optimization, cable-stayed, bridges, cable spacing, deck stiffness, vertical deformation 1. Introduction Many types of bridges are used these days. The sim- plest bridge, the beam bridge, consists of two piers and one beam. However, the need for spans with long dis- tances proposed new alternatives such as suspension bridges and cable-stayed bridges. The cost of the sus- pension bridges is relatively higher than the cost of the cable-stayed bridges and this is one of the advantages of the cable-stayed bridges. The cable-stayed bridges are more economical for spans up to about 1000 m. The diversity of shapes and forms of cable-stayed bridges intrigues even the most-demanding architects as well as technically innovative and challenging. ∗ Corresponding author. Rajai Z. Al-Rousan, Department of Civil Engineering, Jordan University of Science and Technology, Irbid, Jordan. Tel.: +962799887574; Fax: +96227201074; E-mail: rzalrousan@just.edu.jo. The elastically supported girder is the main tools in the simulation of the behavior of a cable-stayed girder. The square of the spacing is proportional to the local bending moment between the cables. The newly pro- posed design necessity that all cables be independently expendable makes closely spaced cables more attrac- tive. It is generally essential that one cable can be dismantled, detensioned, and replaced under reduced traffic loading. The small cable spacing will not increase extremely the additional bending moment in the girder. Accessibility of ever more best computer tools helps engineer to simulate and analysis of the complexity of structure [1–17]. Fiber reinforced polymers (FRP) are started to expand in the field of FRP cables and/or a FRP cable- stayed bridge. The main advantages in the using of FRP is superior strength and light weight which can be uti- lized to enhance the load-carrying efficiency and the 1573-2487/14/$27.50 © 2014 – IOS Press and the authors. All rights reserved