Research On The Stability Of Steel-concrete Composite Beam Under The Action Of Concentrated Load

Steel-concrete composite beam structure in civil engineering construction is the important form of the building structure, the bearing capacity effectively for practical engineering significance. However, the current steel-concrete composite beam structure for stability calculation method and structural design also have a more explicit standards and norms, so give the project of great inconvenience. Based on the analysis and summary of recent years steel-concrete composite beam structure stability theory and actual basis, will from the following several aspects under the action of concentrated load of steel beams and concrete combined beam structures in lateral buckling problem undertakes the studies:1) According to the actual under the action of concentrated load beam concrete composite beams deformation characteristics, establishment of composite beam under concentrated load structure flange lateral bending instability mechanics model and mechanics model of lateral bending and torsion. By using the method of energy, respectively, for two models of structural deformation potential energy, and according to the principle of stationary potential energy, using the variational method, structural buckling load for. And through to the two model comparison, to determine the mechanical model and computational method;2) Under concentrated load beam concrete combination beam lateral bending instability problem on the basis of the analysis, system analysis under the action of concentrated loadπ type steel concrete composite beam structure buckling instability problem. Introduction of concrete flange plates and connecting pieces of the rotational stiffness, simulation of wing plate and the connecting piece on the composite beam top flange torsional deformation constraint function, is established on the basis of the overall structure of the instability model, using energy method, the whole structural deformation potential energy, and according to the principle of stationary potential energy, using the variational method, the structure of buckling load were obtained, for convience of conclusion model twice simplified;3) Based on the two models of critical buckling calculation method is verified, and with comparison of the domestic and foreign model and calculation method of stability, verify the feasibility of the model and method of calculation. Through the calculated results, so as to provide reference for practical engineering design.