Study On The Theoretical Research And Hysteretic Behaviors Of The Steel – Concrete Composite Deep Beams

Composite deep beams are composed with steel plate and concrete slab which connected by high strength friction grip bolt. Composite deep beams have the same placement with shear walls in frame structure. By changing width of the deep beam, we could have different lateral stiffness to meet the requirements of two endpoints and can achieve a wide range of stiffness gradient amplitude modulation. By using different steels and concrete, we could achieve different strength, ductility and energy dissipation capacities. Lateral precast reinforced concrete plate can stop buckling of steel plate without stiffening rib. Lateral precast reinforced concrete plate and steel plate are connected with bolts. When the Composite deep beam is under horizontal seismic action, steel plate bears the lateral loads while reinforced concrete plate doesn’t bear any lateral loads. The reinforced concrete plate provides fire protection to steel plate. In addition, Composite deep beams are flexible layout and they are easy to the aisle and window layout. They can be used to the new structure as well as structural reinforcement. So they have theoretical research value and broad application foreground.Firstly, the development and the behavior of steel–concrete composite deep beams are introduced by analyzing the study actualities about the deep beams around the world. In this paper, low cyclic loading test method is employed to study on the experiment of two pieces of Composite deep beams of different depth-width ratio. By analyzing the hysteretic loops, skeleton curve, distribution of stress, deformation behavior, ductility coefficient and the energy dissipation coefficient of each specimen, we can get the influence of different depth-width ratios on hysteretic behaviors.Next, nonlinearity is introduced in the contact analysis by finite element software Ansys to precisely simulate the work. By comparing with the results of low-cycle loading test, the final results indicate that those two have a better match. So the results from analysis by finite element software Ansys can be used safely. Then apply the nonlinearity method to analyze series of parameters which can influence the performance of Composite deep beams structure system for getting the impact law of depth-width ratio, depth-thickness ratio of the steel plates and concrete slab, the intensity of steel plates and concrete slab, the ratio of reinforcement and the bolt form.Base on the low cyclic loading test data, the skeleton curve and stiffness of each load through test is analyzed, the result show that: The nonlinear behavior of the composite deep beams structure system can be expressed more perfect by using tri-linear model with consideration of rigidity degradation,and the skeleton curve of the restoring force model and the loss law of the structural rigidity which laying the foundations for elastoplastic anlysis are obtained by fitting to the experimental date and the theoretical calculationBased on the model of simplified calculation of composite slabs, three calculation formulas and its initial stiffness of the simplified computation model is presented by using the model of simplified calculation of composite slabs. What’s more, a series of Ansys finite element analysis of the three models have been done, and the results show that: The simplified computation models are clear in physics meanings and simple in calculating, and each model has its own characteristics and lays emphasis on different aspects. The equivalent strut model is applied to analyze the initial stiffness and yield strength of the composite deep beams. The chevron brace simplified calculation model is suitable for simulating the nonlinear behavior.Finally, by using Abaqus to analyze the dynamic elastoplastic of super high rise building structure with composite deep beam under strong seismic action, we obtained displacement response of vertex and lateral damage process of Core Tube and response of base shear. Moreover, the results show that the composite deep beam can improve the lateral performance of the structure, regulate the rational distribution of earthquake force of the frame-tube structure and make full use of anti-seismic action of frame.