| In recent years,with the development of social economy and culture,people have higher and higher aesthetic demand and using demand for buildings,and the traditional structural form is not completely applicable.Aluminum alloy grid structure has been widely concerned by virtue of its material advantages and overall advantages of spatial grid structure.At present,aluminum alloy grid structure is often connected by assembly node,among which aluminum alloy hub node is simple to form,easy to install and low comprehensive cost,which has good engineering application value.So far,it has been used in more than 35 countries around the world,but there is still a lack of relevant research in China.In order to ensure that the hub type aluminum alloy joints will be introduced and used more in the future,it is of great significance to study the mechanical properties of the joints and the stability of the single layer spherical reticulated shell.In view of the above background,this paper mainly carries out the following work:(1)Based on the finite element software ABAQUS,refined numerical models are established for two kinds of aluminum alloy hub-type nodes with different sizes.The deformation characteristics,failure modes,stress distribution and ultimate bearing capacity of the joints are obtained by simulating the tensile,compressive and flexural behaviors of the joints.The influences of factors such as slot spacing,tooth width and tooth depth on the ultimate bearing capacity of the hub are determined.The formulas of ultimate tensile and flexural capacity of aluminum alloy hub joints are presented,and the recommended value range of the influencing parameters and the design Suggestions of the hub diameter are given.(2)Based on the finite element software ANSYS,the influence of the bending stiffness of hub-type joints on the overall stability of single-layer spherical reticulated shell was studied by using the spring element simulation of node connection.By introducing the bending moment-angle curves of the nodes obtained above,the overall stability performance of the K8 type aluminum alloy hub-type lattice shell with different spans,different rise-span ratios,and different in-plane and out-plane bending stiffness is analyzed,and the instability modes and ultimate bearing capacity of the lattice shell are obtained.The influences of span,rise-span ratio and in-plane and out-plane bending stiffness on the stability of K8 aluminum alloy hub-type lattice shell are determined.In this paper,the formula of ultimate bearing capacity of aluminum alloy hub type joints is put forward,and the corresponding Suggestions for the design ofjoints are given.It is determined that aluminum alloy hub-type node can be considered as a semi-rigid node,and the influence of in-plane and out-plane bending stiffness on the stability of reticulated shell is summarized,which is of reference significance for the design and application of such node in the future and the revision of relevant specifications. |
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