Stability Analysis Of Steel Tube-Confined Concrete Reticulated Shell

Reticulated shell structure can cover more space in a smaller cross-sectional area, it has novel and lively form, aesthetics, artistic expression, and thus received an unprecedented development. However, with the structural span becomes larger and larger, the thickness becomes thinner and thinner, the materials becomes lighter and lighter, the stability of the structure becomes very prominent. Therefore, this paper describes steel tube-confined concrete (STCC) reticulated shell structures, which is a new space reticulated shell structures. Concrete is poured to steel tube, using STCC with the advantages of high compressive strength, good plastic and toughness, to reduce the amount of steel, lower costs, improve the stability of the structure and its mechanical properties. The main content is described as follows:(1) The paper researches on the development of the STCC composite structure, the basic working mechanism and characteristics of the components, and the material model of simulate components. the United Theory for STCC is used to determine the behaviors of the composite material.(2) On the basis of the theory and methods of the non-linear complete process analysis on reticulated shell structure, this paper deduces the tangent stiffness matrix of nonlinear spatial beam element; discusses the computational method of load-displacement complete process tracking of the single-layer spherical reticulated shell.(3) Based on the fundamental structural stability theory and space nonlinear finite element, by means of finite element analysis program ANSYS, this paper models and resolves the widely used K8 single-layer spherical steel reticulated shell and single-layer spherical STCC reticulated shell, draws the load-displacement curve of steel reticulated shell and STCC reticulated shell under different span, rise-to-span ratio and beam section dimension. Considering the current market price of steel and concrete, the paper made a comparative analysis of the two concrete reticulated shell on self-weight, bearing capacity, steel volume, costs, etc. and pointed out the superiority of STCC reticulated shell.(4) Through the complete process tracking of the STCC reticulated shell, the paper makes nonlinear load-displacement complete process tracking analysis for STCC reticulated shell, and not only draws the load-displacement curve for largest displacement nodes of every structure at the end of iterative computer, but also gets limit load of every structure. Through large-scale parameters analysis, the paper reveals the basic characteristics of the stability and the instability mechanism for single-layer STCC reticulated shell structure. Discusses the law of the stability under different parameters (such as rise-to-span ratio, grid density, beam dimension, boundary conditions, initial shortage).Finally, concluding remarks and avenues for future research are stated.