Experimental Research And Numerical Simulation On Mechanical Performance Of Grid Structure With New Type Of Rotating Plate

At present,the design of architectures tend to be super high-rise,large span,large cantilever,and other structural forms with complex stress.According to the traditional technology,it is often necessary to set up complex construction platforms as supporting system.To simplify the construction technology,this paper puts forward a new temporary supporting platform—grid structure system with new type of rotating plate.The basic elements of grid structures are tested to study their bearing capacity,including mechanical behavior,deformation and stress distribution,such as rods,welded hollow spherical joints,etc.Three large-span grid constructions with different forms are designed,the mechanical property test and numerical simulation analysis are carried out to study the bearing capacity,deflection and stress distribution of the grid structure.It provides the application basis and theoretical basis for the engineering application of the grid structure with new type of rotating plate.(1)The rods were subjected to an axial-force test,to study the effect of taking low alloy high strength steel as the base material of the rods on their bearing capacity.By arranging strain measuring points on the rods,the stress distribution in different sections of the rods under the effect of axial-force was studied.The axial-tension test showed that the tension failure of the rods occurs at the joint between the end plate and the tube,which is mainly affected by the heat affected zone of the weld and the stress concentration effect;The axial compression test results showed that the high strength steel can significantly enhance the bearing capacity of the rods.Through the comparison between the test values and the calculated values,the bearing capacity and deformation of the rods are all met the requirements.(2)According to the displacement and the strain data of the spherical surface,the relationship curve of load with displacement and strain was drawn.The stress distribution of the spherical joints under axial load was obtained.The test result showed that the tension performance of the hollow spherical joints was related to the strength of the claw-shaped end plate of the short rods,the compression performance was significantly enhanced with the increase of the outer diameter,wall thickness and material of the hollow sphere.The bearing capacity of the hollow sphere joints met the design requirements.(3)Three large-span space grid structures with rotating plate are designed and tested to study the bearing capacity,including the double layer basic space grid,double layer prestressed space grid and three-layer prestressed space grid.The load-displacement curves of the lower chord nodes and the stress-strain curves of the members are plotted to analyse the influence of different strengthening measures on the overall bearing capacity,deformation behavior and the stress law.Compared with the basic double-layer space truss,the prestress in the lower chord can effectively improve the bearing capacity of the space grid structure and control the natural settlement deformation of the structure.The bearing capacity of three-layer space grid structure can be improved obviously and the deflection can be further limited by prestressing the lower chord.(4)The finite-element analysis of the grid structure was carried out by the ANSYS software,and compared with the test results.The force characteristics of the members in the finite element model are in good agreement with the test results,and the joints’ displacement of the grid structure met the requirements of the deflection limit in the code.Through experimental study and theoretical analysis,the grid structure with new type of rotating plate has good bearing capacity performance.It’s easy to install and disassemble,also can significantly save construction materials;According to the project requirements,the grid can be assembled into various forms of space structures,which provides solutions and test basis for the construction problems of super high-rise,large-span,large cantilever and other structures.