Study On Steel-concrete Composite Dome Joints

The steel-concrete composite rib net is an orthogonal shell structure composed of U-section combined ribs.Firstly,three thin steel plates are welded into U-shaped steel ribs,and steel rib net shells are formed according to orthogonal arrangement,and then poured in the grooves.The steel rib reticulated shell is formed according to the orthogonal arrangement,and the concrete is poured into the trough to form a steel-concrete composite rib net.This type of structure can make full use of the tensile properties of steel and the compressive performance of concrete.Compared with the general steel reticulated shell structure,the structure has high stability and bearing capacity,and is a spatial structural form with broad application prospects.This type of structure can make full use of the tensile properties of steel and the compressive performance of concrete.Compared with the general steel reticulated shell structure,the structure has high stability and bearing capacity,and is a spatial structural form with broad application prospects.Applicable to large-span,large-space exhibition halls,stadiums,terminals,etc.In this paper,the combination of experimental research and numerical simulation analysis is used to study the performance of steel-concrete composite dome joints.The1:10 model is used to carry out the semi-span load of the whole structure and the static loading test under the concentrated load.The internal force distribution under the overall structural load is used to analyze the spatial force and deformation of the combined joint.Based on the finite element theory,the node numerical analysis model is established.In order to improve the stress performance of the node,the improvement measures of the node are proposed.The parameters of the improved node are analyzed to analyze the node failure ability,stiffness,energy dissipation,ductility and residualdeformation.The main research contents and results are as follows:(1)Perform static performance tests on combined ribbed specimens under concentrated load,half-span and four-point loading,and analyze static indexes such as structural crack initiation,stress distribution and structural deformation characteristics.The bearing capacity of the combined dome structure,the stress and strain of the steel plate and the internal concrete are studied.The failure mode and failure process of the composite dome under static load are revealed,which provides guidance and basis for further optimization of the structural design.A numerical calculation model was established to analyze the mechanical properties of the structures under different loads.The experimental results are compared with the numerical simulation results.The results of the finite element simulation agree well with the experimental results.(2)Extracting the node data in the static loading test model,and analyzing the spatial force performance of the combined joints in the test.The study shows the combined U node with the re-distribution of internal forces as the load increases,the cracks develop locally.The deformation of the wall panel and the crushing process of the inner concrete were recorded,and the stress-change law during the test was recorded.A numerical calculation model was established to simulate the entire static loading process and compare it with the experimental results.The study found that the original joint steel plate is not completely wrapped in the concrete,the node connection is weak,and the node energy consumption is poor.In this paper,two kinds of node enhancement schemes are proposed.After comparison,the seismic performance of the nodes is improved under the all-inclusive steel reinforcement scheme at the loading node,and the parameter analysis is carried out to help analyze the nodes in the future.(3)Perform seismic performance analysis on the improved nodes.The basic theoretical knowledge of seismic performance is described,including the establishment of models and unit selection.The seismic behavior of the joints under different angles and steel plate thickness is discussed.The load-displacement curves of each model are obtained,and the energy dissipation capacity and displacement ductility of the model are studied.The research shows that the hysteresis curve of numerical simulation is full shuttle shape,and the positive and negative directions are basically symmetrical.Withthe increase of angle,the bearing capacity of the model is reduced,but both show good seismic performance.When the thickness of the bottom plate is increased,the seismic performance is improved.