Analysis and design procedure of hybrid long-span cable-stayed bridge using advanced composite material

Abstract

An innovative solution is proposed in this paper by introducing a hybrid-type cable stayed bridge as a competent system to safely bridge very long spans. The new system leads into huge reduction in deck weight and its critical stresses in the pylon zones by using hybrid advanced composite deck. It also reduces the stiffness losses of the stay-cables due to the catenary’s action by using carbon fiber reinforced polymer cables. The paper proposes a proper consistent and systematic analysis and design procedure that optimize and precisely simulate the proposed bridge system. It recognizes the changes in structural behavior of the cable-stayed system, accordingly it clearly defines the ultimate and serviceability limit states for such new structural system in consistence with the limit state design philosophy. The design steps of the ADP represent a multi-scale design technique while the analysis steps characterize a multi-scale modeling technique. They represent the material design in the micro/macro-level, and accurate homogenization of the advanced composite components properties and evaluation of the resulting anisotropic characteristics and then, three-dimensionally simulate the hybrid bridge system involving all its nonlinearities. This paper investigates the performance of a new hybrid long-span cable-stayed bridge, which engages the use of advanced composite materials for the deck and the stay-cables, applying the analysis and design procedure. This design is scaled to match the general geometrical shapes, structural and aerodynamic characteristics of three of the world-longest cable-stayed bridges. What’s more, four advanced composite deck section models are proposed in this research. In order to study the performance of the referenced bridges, such as the natural frequencies, the deck top surface maximum vertical displacement, maximum Tsai-Hill failure function and the critical flutter velocity, three sets of parameters are investigated. The parameters include: (i) the micro level parameters-fiber fraction, (ii) the macro level parameters-Laminas Dominant Fiber Alignment and Laminate Thickness and (iii) the structure level parameters- cable radius.