Overall Stable Analysis Of Multilayer Space Steel Frame

At present, both at home and abroad, the stability of steel frame is studied mostly by studying the stability of frame column to indirectly guarantee the stability of the steel frame, while the studies of overall stability of space steel frame are rare. Yet the practical structure of framework is space structure. This article begins with the overall stable performance of the structure, considering the interaction of components, a deep research on the stable performance of space steel frame in relative stiffness changes of beams, slabs, and column is done to better coordinate the stable bearing capacity of structure, which has very important practical significance to guiding the design work.Considering material nonlinearity and geometric nonlinearity, using ANSYS finite element method of nonlinear the stable performance of special steel frame is studied, and the real stress state of it in various circumstances is simulated. Through four series of 12 specimens of calculation and analysis, the article mainly studies the changes of stable bearing capacity of steel frame in plus load, and the effect of relative stiffness of beams, slabs, and column, and floorslab hole to overall stable performance. Analysis results show that the thickness of floorslab, the decoration of floorslab hole and column sectional dimension have a great influence on the stable bearing capacity of steel frame structures. Columns stiffness determines the maximum stable capacity of the framework, and the stiffness of the floorslab determines whether the structure can reach stable of bearing capacity. When the concrete floorslab hole exists, the hole has great influence on stable bearing capacity of irregular plane layout of framework. To guarantee the overall stability of structure, this paper puts forward that within the multi-storey steel frame, when regular plane layout is used, the thickness of floorslab shall remain above 150mm; when irregular plane layout is adopted, such as L layout, the thickness of concrete floor should keep around 200mm; in floorslab hole circumstance, holes in the corner of structure should be avoided; and when holes of each floor are opened at the same time, the limits of porosity should be changed to 30%, which is good for improving the stable performance of steel frame structure.The thinking of establishing finite model is comparatively comprehensive, which has high precision and can simulate the real stable performance of multilayer space steel frame in plus load carrying capacity. The stable performance of multilayer space steel frame in various structural stiffness are deeply analyzed, and the research work and conclusions have the certain reference value for guiding the engineering design and lay a good foundation for the further research of overall stability of multilayer space steel framework.