Restrained Torsion Theory Analysis Of Open Thin Walled Beams Considering Shear Deformation

Open thin wall beam under the same cross sectional area can gain greater stiffness, and they are widely used in various building structure and bridge engineering. In order to ensure its normal work, it is very important to established in accordance with the actual deformation of open thin-walled physical model, the traditional Vlasov theory due to seize the main deformation characteristics and widely used in engineering, but the theory ignores the influence of the secondary shear stress on the structure performance, makes its application limited. In order to include the effect of shear deformation, in this thesis, including the effect of shear deformation thin-walled beam theory is developed based on Vlasov theory, the main research content is as follows:1?This paper mainly discusses the static behavior of open thin wall beam restraint torsion, to consider the influence of shear deformation open thin wall beam restraint torsion theory deduction, gives a general solution of initial parameter method, and was deduced in different torque load and boundary conditions of displacement and internal force of expression.2?For considering the effects of shear deformation in the theory of open thin wall beam restraint torsion shear stress non-uniform coefficient, several common open thin-walled cross section shear stress the exact expression of non-uniform coefficient, analyzes the torsion shear stress non-uniform coefficient with high aspect ratio, thickness ratio and the effects of parameters such as generous than the rule.3?Given considering the effects of shear deformation and the analytical solution of open thin wall beam restraint torsion formula is more complex, this article to get and a simplified formula similar to the Timoshenko beam theory and explores of saint-venant torque can be ignored, this paper expounds the simplified method and considering the effects of shear deformation between error sources, the definition of shear deformation influence parameters, gives the different structure between the simplified method and the analytic solution under different load torque needed to reach 5% of the error conditions; Type of slot section and Z section beams the example verification and parameter analysis, quantitative analysis of the various size error between the theory and considering the shear deformation theory and vary with parameters and draw the relevant conclusions.4?Of open thin wall beam under transverse and longitudinal eccentric load analysis ofthe constrained torsion will open thin wall beam is considered as a plus double eccentric load torque, some common structure was deduced under eccentric load deformation and internal force of expression; Of groove type cross section under vertical load example verification and parameter analysis, quantitative analysis of the various size error between the theory and considering the shear deformation theory and vary with parameters and draw the relevant conclusions; At the same time analyzes the buckling stress of the trend of the percentage of the total stress vary with parameters and relevant conclusions are drawn.5?For open thin wall beam bending center under the lateral load formula is no longer applicable.