Optimization of the economic practicability of fiber-reinforced polymer (FRP) cable-stayed bridge decks

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.