Optimal Design Of The Orthotropic Plate Of Steel Box Girder

In this paper, the problems of the local buckling properties,fatigue properties of stell box girder and the durability of the deck pavement were well studied. And then, systematic optimization analysis models were put forward. The theoretic achievements of the paper are as show below.(1) The origin, development course and present state of the orthotropic deck of steel box girder are been introduced. Key problems of its mechanics analysis are as follows: local buckling properties,fatigue properties and durability of the deck pavement. The application status and necessity of the optimization analysis theory is been preliminary studied.(2) The fundamental form of the orthotropic steel box girder's components is briefly studied. And theoretical results of the buckling properties of quadrilateral simply supported slab are studied. This basic steps of fatigue assessment includes: fatigue load spectrum,stress amplitude and S-N curved line. This paper introduced the common forms and force-bearing characteristics of the steel bridge deck pavement.(3) The equivalent girder beam method is used to analyse the second stress of orthotropic deck system. Comparing to P-E method and the finite element method, the above-mentioned method meets the accuracy requirements and shows high efficiency. So, it should suitable to the optimization analysis.Related articles of the Japanese bridge specifications conforms the design method of local stability of stiffened plate. And the results of the finite element analysis verify the reliability of it.In the FEM model, the steel deck system is simulated by shell and solid element. This model systematical analyses the infulunce of material property, construction features and over loading to the pavement.(4) The optimal model takes favorite structural form as design variable, and the structural weight as objective function. According to the basic principle of optimal design, this chapter establishes two analysis models which use the equivalent girder beam method to analyse the second stress of orthotropic deck system. The influence of the pavement to optimal model is considered in model 2 which receive some meaningful conclusions. Finally, model 2's fatigue property is been checked.