Design For Typical Stiffened Compression Plates Of Steel Box Girder In Cable Stayed Bridge

Recently, while a long span steel box girder cable-stayed bridge has a rapid development all over the the word, it has also followed with a lot of stability problem of the steel box girder. Stiffened plate is an important part of the thin-walled steel box girder, which as the main object of study. Under the commission of National Natural Science Foundation of China (50608005), the stability of stiffened plate under the compression what is the basic and the common performance is discussed. At last, a design method of the typical longitudinal rib stiffened plate is proposed.The main design and computational theories of stability of stiffened plate are summarized, it is obtained stiffened plate theory based on correlation analysis of the overall design idea; common used computational theories and methods of the stiffened plate design method are elaborated, there are elastic stability theory, ultimate capability method and numerical analysis method.On the elastic stability theory, four kinds of failure modes are decribed by the finite element model. According to the classical stiffened plate stability analysis and calculation theory, the critical buckling coefficient is introducd, which due to the stiffener flexural rigidity ratio and the size parameters of the stiffener, and then the focul poit of the design method and calculation of the elastic stability of stiffened plate is proposed. In the ultimate capability method of stiffened plate, considering the initial defects and residual stress of stiffened plate, the focul poit of the ultimate capability calculation of the stiffened plate is proposed. Finally, according to the parameters, the sizes of stiffened plate can be placed.The classical calculations of stiffner rigidity ratio and stiffened plate effective width are analyzed that are the main factors influence the critical elastic buckling stress and ultimate bearing capacity of the stiffened plate, and also summarize the parcial sizes of the stiffened plate from spesifications from home and abroad. There is the comparative analysis about spesifications.The elastic stability design of stiffened plate is given. An opening flat rib stiffened plate design method is summarized from regulations in the spesifications. The design method is concise and clear, and is easy to use in the design and calculation of stiffened plate. There are data simulation and analysis from ANSYS finite element model of elastic stability critical buckling stress of stiffened plate by changing the parameters such as stiffener rigidity, aspect ratio, stiffener spacing and thickness of the motherboard, etc. There is calculation and analysis for ultimate bearing capacity of stiffened plates, according to the standards of United States and Japan. The results show that the value of American standard is closer to ansys, but the two standards also have certain limitation. It is useful for such design.