Improved finite strip method for nonlinear analysis of long-span cable-stayed bridges

As the spans of cable-stayed bridges increase, the degree of nonlinearity of structural response increases markedly. For future spans greater than (say) 800 m, existing three-dimensional software then becomes very time consuming and costly, and a finite strip approach becomes more attractive and preferable. An improved finite strip method using two types of longitudinal shape functions is developed in this paper for the analysis of girders of such bridges. The nonlinearities due to sag and angle change of the cables are taken into account by means of catenary theory. The substructuring technique and the modified Newton–Raphson iteration method are used for nonlinear solutions. A number of numerical examples are given to show the accuracy and efficiency of this method. Key words: finite strip, continuous structure, cable-stayed bridge, substructuring, catenary, nonlinearity, iteration.