2001 Volume 8 Issue 30 Pages 39-49
Dealt with in this paper a method for deciding the proper shape of initialdeformation for elasto-plastic and finite displacement analysis of rigid framed steel bridge structures through using a Nielsen-Lohse bridge model as an example. In themethod, an elasto-plastic buckling mode in the vicinity of the ultimate limit state, which can be approximately obtained without executing eigenvalue analysis, is adoptedas the proper initial deformation shape. Proposed in this paper also is a method for finding out structural members of which strength affects predominantly the loadcarrying capacity of steel bridge structures by comparing with the results of elastoplastic and finite displacement analysis of two models. One is the model idealized withelasto-plastic finite elements, and the other one is the model in which the structuralmembers under consideration are idealized with elasto-plastic finite elements and theother members are idealized with elastic finite elements. Effectiveness of the method isverified by using two numerical models of cable-stayed bridges.