Static Analysis of Suspension Bridges

Abstract

With the advent of digital computers it has become possible to analyze suspension bridges taking account of hangers as individual members. As the behavior is nonlinear satisfactory convergence is most likely to be obtained in the solution of the governing equations if a Newton-Raphson method is used for correcting the basic variables. Compatibility and equilibrium methods are developed which produce symmetric equations to be solved at each iteration. By suitable choice and ordering of the variables these equations can be made to fit well into a variable bandwidth store thus producing an efficient form of computer solution. The most efficient of these methods is the compatibility method in which the horizontal component of hanger force is ignored. In cases where the stiffening girder is a Warren truss the compatibility method also shows advantage, but in other cases the equilibrium method is likely to be preferred because the equations are more easily constructed.