Effect of cable stiffness on a cable-stayed bridge

Cables are used in many applications such as cable-stayed bridges, suspensi on bridges, transmission lines, telephone lines, etc. Generally, the linear relationship is inadequate to present the behavior of cable structure. In finite element analysis, cables have always been modeled as truss elements. For these types of model, the nonlinear behavior of cables has been always ignored. In order to investigate the importance of the nonlinear effect on the structural system, the effect of cable stiffness has been studied. The nonlinear behavior of cable is due to its sag. Therefore, the cable preten sion provides a large portion of the inherent stiffness. Since a cable-stay ed bridge has numerous degrees of freedom, analytical methods at present ar e not convenient to solve this type of structures but numerical methods may be feasible. It is necessary to provide a different and more representativ e analytical model in order to present the effect of cable stiffness on cab le-stayed bridges in numerical analysis. The characteristics of cable defor mation have also been well addressed. A formulation of modified modulus of elasticity has been proposed using a numerical parametric study. In order t o investigate realistic bridges, a cable-stayed bridge having the geometry similar to that of Quincy Bayview Bridge is considered. The numerical resul ts indicate that the characteristics of the cable stiffness are strongly no nlinear. It also significantly affects the structural behaviors of cable-st ayed bridge systems.