Mechanical Property Analysis on Joints of Steel Secondary Beam Inserted in Reinforced Concrete Frame Girder

Models for internal force analysis and strain distribution of joints of steel secondary beam inserted in reinforced concrete frame girder were analyzed. The horizontal internal force and vertical force were considered separately during calculation and analysis process. Bending-shearing correlation of vertical internal force was studied while the horizontal force wasn’t taken into account. Results show that the non-dimensional moment varies linearly with the non-dimensional shear force. Base on this, the formulas by which the joint moment and shear force are calculated are derived, and are related to depth ratio of forward to backward compression zone .And then the method to calculate joint moment capacity under horizontal force is put forward. By investigating the moment and shear force variation, the relationship between the yielding stress of the bar in the slab and the boundary concrete under the steel secondary beam crushing is identified. In the end, practical design method is proposed, and problems need further research are mentioned.