Evaluation of the Static and Dynamic Behaviors of Long-Span Suspension Bridges with FRP Cables

To overcome the limitations of traditional long-span suspension bridges with steel cables, the mechanical behavior of suspension bridges with various fiber-reinforced polymer (FRP) and hybrid FRP cables have been investigated comprehensively. The authors adopted a prototype of the proposed Messina Strait Bridge with a main span of 3,300 m to use as a suspension bridge model for analysis. The static and dynamic behaviors of the entire suspension bridge with steel and different FRP cables were analyzed by using the finite-element method. The results indicate that the application of FRP cables in a long-span suspension bridge benefits the spanning ability, improves the load-carrying efficiency, and reduces the axial force of the cable. The modal analysis results show that the long-span suspension bridge with cables of different materials have similar mode shapes, although the natural frequencies of the bridges with FRP cables are larger than that of the bridge with steel cable because of lower self-weight. It is also revealed that the adoption of FRP cables decreases the seismic responses of the suspension bridge because of their better energy-dissipation behavior, and FRP cables improve the flutter critical wind speed and contribute to the overall aerodynamic stability of large-span suspension bridges.