Study And Analysis On Welded Hollow Sphere Joints Of Base In Pipe Truss Structure

The spatial structure has the advantages of reasonable force,light weight,low cost and lively and innovative form,which can highlight the advantages of human art creativity and is widely used in practical engineering.The key factor in the design of space structure is the node structure design.Welded hollow ball nodes are widely used in various types of space structures with their own unique advantages,because it can be connected in any direction of space,easy to arrange.Especially for the long-span space structure of the bearing node,so easy to the lower part of the sliding,articulated and fixed bearing connection.In this paper,the finite element software ABAQUS is used to numerically simulate the multi-directional large-diameter welded hollow ball bearing joints,and the parameters and structures of the welded hollow spherical joints are found by changing the parameters.Specific research as follows.Welded hollow ball nodes are widely used in all kinds of space structures,especially the grid structure,because of its unique advantages.It can be connected in any direction of space.It can be applied to the support of the large span space structure,because it can be easily connected with the lower part of the sliding,articulated and fixed bearing connection,and fixed on the lower supported.In this paper,we mainly use the large-scale general finite element software(ABAQUS)to simulate the nodes in the multi-directional large-diameter welded hollow ball bearing joints in practical engineering.By changing the parameters,we can find out the welding holes form.(1)Finite element software ABAQUS was used to simulate the welded hollow spherical joints under uniaxial tension and pressure,and the reliability of the analytical method was verified by comparing with the experimental results in the literature.The ultimate bearing capacity of welded hollow spheroids is analyzed,and the influencing factors of bearing capacity of large diameter welded hollow spheres are studied and the failure mechanism is studied.(2)Based on the design of the joints of the actual pipe truss engineering,ABAQUS is used to simulate the large diameter welded hollow spherical joints,and the influence of the stiffening ribs on the bearing capacity of the welded hollow spheres is studied.The results show that the single ring stiffener can not improve the mechanical performance of the ball joint,and the cross bar improves the bearing capacity.(3)In this paper,a new type of stiffener arrangement is put forward according to the actual characteristics of the project and the connecting rod.The numerical analysis shows that the node with this stiffener is satisfied to meet the engineering requirements.It is suggested that the compression capacity of the welded hollow spherical joint of this new type of stiffener should be 1.2.The results show that the width of the stiffener has a great influence on the bearing capacity and the thickness is not significant.In order to avoid stress concentration,the thickness of the value should not be too small.(4)Aiming at the actual force of the welded hollow sphere,the calculation method of the axial force flexibility is proposed,and the 48 sets of ribbed ball nodes are simulated.The practical calculation formula of the axial force flexibility of the welded hollow spherical joint is fitted according to the simulation data.