Stress Mechanism Of Frame-Supported Multi-Ribbed Composite Wall Beam And Structural Seismic Design Theory

Frame-Supported Multi-Ribbed Composite Wall Structure is a new anti-seismic structure system with large space Frame-anti-seismic Wall (Composite Wall) Structure at the bottom and Multi-Ribbed Composite Wall Structure at the top. The Multi-Ribbed Composite Wall Structure has such advantages as light weight, good integrality and high bearing and dissipated capacity, and the bearing capacity and stiffness of the structure can be adjusted according to different design requirements, therefore, it is easy to make the vertical rigidity between the bottom large space and the upper structure harmony, which improves the seismic performance of the whole structure. As the most important transfer member between the upper and the bottom structure, the wall beam plays a decisive role in the seismic performance of the whole structure. So, the research on the stress mechanism and anti-seismic design theory of the wall beam is especially important.In the paper, the experimental researches, theoretical analysis and numerical simulation are used to studies the load-bearing performance and influence factors of the wall beam under the vertical and horizontal loads. The simplified mechanical model of Frame-Supported Multi-Ribbed Wall Structure is established and the practical design calculated methods for wall beam are proposed. Meanwhile, the reasonable stiffness ratio between structural interlayer has been discussed and some details of seismic design for Frame-Supported Multi-Ribbed Composite Wall Structure are provided. The main contents are presented as follows:1. Aseismatic capability Experimental study of Frame-Supported Multi-Ribbed Wall Beam and the bearing capacity of the wall beam under vertical load (Innovation No:1)To study the the reaction of Frame-Supported Multi-Ribbed Composite Wall Beams under vertical and horizontal low-cyclic loading , Through the experimental study on four pin and two-scale models, the force mechanism , failure modes and the seismic performances of the wall beam are studied, in which the bearing capacity and the influence factors of the wall beam under vertical load are mainly discussed.2. Nonlinear Finite Element Analysis for the Frame-Supported Multi-Ribbed Wall BeamIn order to solve the entity experiment limitions of examination quantity,condition of work and load ,reveal the Frame-Supported Multi-Ribbed Wall Beam's mechanics behavior, Based on the nonlinear FEM analysis on the Frame-Supported Multi-Ribbed Wall Beam, the whole process of the internal force , deformation, cracks-development and the ultimate bearing capacity of the wall beam are well simulated. Meanwhile, the verified finite element analysis models are used to obtain more reaction information of the wall bean, which lays a foundation for establishing a more effective calculation model of the wall beam.3. Study on load Reduction of Frame-Supported Multi-Ribbed Wall Beam and practicality design method (Innovation No: 2)In order to simplify the Frame-Supported Multi-Ribbed Wall Beam's design and calculation method by means of convert the upper loads to wall beams's calculation loads, According to the experimental results, the verified finite element model is used to analysis of the bearing characteristic of frame-supported multi-ribbed wall beam under the vertical load. Meanwhile, the comparison and analysis of the four mainly factors which influence the stress distribution of trimmer beam of composite wall is carried out in this paper, such as the ultimate load of the trimmer beam and the height-to-span ratio of the wall,the height-to-span ratio of the trimmer beam,the ration of elastic modulus of the wall and the trimmer beam,opening holes and position and so on. Based on the theory of elastic foundation beam, the triangle series stress distribution of the trimmer beam under vertical load is established. At the same time, the load reduction coefficient of trimmer beam is taken back , and a more practical, simple and convenient calculation and design method is carried out, which provides a scientific basis for the practicality design of the Frame-Supported Multi-Ribbed Composite Wall Structure beam.4 Study on Optimization design of Rigidity Ratio between Stories of Frame-Supported Multi-Ribbed Wall Structure(Innovation No: 3)In order to solve the problem of The reasonable value of Rigidity Ratio between Stories of Frame-Supported Multi-Ribbed Wall Structure, Based on above Experimental study in this paper, Nonlinear Finite Element Analysis,previous research results and the calculation theory of modern high-rise structures, the frame-supported composite elastic slab model as the simplified mechanical model of Frame-Supported Multi-Ribbed Wall Structure in elastic stage is carried out in this paper. Then the verified simplify mechanical model is used to analyze the dynamic response of the structure, and the effect of the rigidity ratio of the upper story and lower story of the transfer story to the structure elastic displacement is discussed. Moreover, the reasonable value is put forward, which preliminary solve the Optimization design difficulty of Rigidity Ratio between Stories of Frame-Supported Multi-Ribbed Wall Structure.5. Seismic Design Method of the Frame-supported Multi-ribbed Frame Wall StructureBased on the comparison of the design methods of several common wall beams, the empirical computing formula of the Frame-Supported Multi-Ribbed Wall Beam is established. In addition, the elastic and elastic-plastic calculation model for the Frame-Supported Multi-Ribbed Wall Structure is put forward. Finally, based on the idea of seismic control, some seismic detail measures of Frame-supported Multi-ribbed Frame Wall Structure and its members are provided.