A SADDLE MODEL IN FINITE ELEMENT ANALYSIS OF SUSPENSION BRIDGES

To model saddles in finite element analysis of suspension bridges,one class of new finite elements were developed,including two-node left-saddle element and right-saddle element that model a cable segment fixed with saddle at one end respectively,and three-node saddle element that models a cable segment fixed with saddle at one point on the cable.The fixed point was selected to be one node in each element.The proposed elements simplify computations by automatically adjusting the departing points.The derivation of element formula is based on the principles of FEM and the analytical solutions of elastic catenary.The relation of the forces between cable and saddle at equilibrium are also used.The saddle weight can be considered in the proposed elements,and the longitudinal curve of saddle can consist of two arcs with different radii.The proposed elements can be incorporated into conventional finite element analysis.Examples demonstrate the accuracies and applications of the proposed elements.