Performance Analysis And Experimental Research On A New Type Of Compound Spherical Joints For Steel Structure

Great-span interspace structure is the quickest developing structure presently. Great-span interspace structure has characteristic of the power in reson, cover with great span, great firm tolerance, light self-respect, sculptrichness and beauty, integrate technical economy target characteristic. Joint has played a very important role in structure, as joint is the critical connection part of structure. A new type of compound spherical joints will be shown in this thesis. It consists of ball body, spacer, connector and steel pipe which assembled by bolt and welding.This type of joints belongs to a compound typical semi-rigid joint which avoids wielding in high altitude and false twisting during construction. This type of joint can totally be prefabricated in factory and reduce the chance of false assemble in construction site. There is no research in its performance under axial load and moment so far.To observe and analyze the stress mechanism and ultimate bearing capacity of this new type of joint under axial load, we use general FEA application ANSYS processing finite element analysis and get a relatively accurate stress mechanism and ultimate bearing capacity. We choose some joints of typical size taking axial load experiment based on finite element analysis before and find the results of this two analysis ways coincide very well. In the process of FEA and experiment, we choose several factors that could influence this joint's ultimate bearing capacity making deeper research and make some suggestions against problems during research we find.Joints not only bear axial load but also bear moment during work in spatial structure. Usually, under consideration of safety, people usually consider this semi-rigid joint as hinged joint ignoring its flexural capacity. In fact, this new type of compound spherical joint has the ability to resist moment and can be used in engineer very easily and widely. It means a lot for this type of joint to explore its performance under different load and stability in monolayer shell, so we make a non-linear finite element analysis considering different type of factors and a series of experiments to get relatively accurate moment-angle of rotation curve and flexural stiffness of this new type of compound spherical joints. The ecperimental results are mostly consistne with the theoretical ones, which indicate that the numerical simulation is accurate and effective to simulate the new type joints's meachanical property. It can serve as stability base for design and application of this new type of compound spherical joints and other semi-rigid joints.The shells with new type of compound spherical joint system have been detailed analyzed based on bending stiffness of the connection. The elastic-plastic complete process of K8 spherical shells are studied, the ultimate strength and buckling modes of shells are obtained, the effects of stability are observed by varying different span of shells, ratio of high and span, bending stiffness, and initial geometrical imperfection. The stability of spherical shells with new type joints system is mastered by a comprehensive numerical analysis.