Nonlinear inelastic dynamic analysis of suspension bridges

In this paper, an accurate and efficient numerical procedure is proposed for the nonlinear inelastic time-history analysis of suspension bridges subjected to earthquake excitations. The proposed procedure includes both geometric and material nonlinearities. The geometric nonlinearities of tower and girder members are taken into account by the use of stability functions, while the geometric nonlinearities of cable members are considered using exact analytical expressions of an elastic catenary. The gradual yielding along the member length and over the cross-section is included using a tangent modulus concept and a refined plastic hinge model. A computer program utilizing Newmark’s average acceleration algorithm with Newton–Raphson iteration is developed. The obtained results are compared with those generated using the commercial package SAP2000 to illustrate the accuracy and computational efficiency of the proposed procedure.