Study On Stiffness Characteristics Of Bearing And New Bearing In Space Structure

With the widely application of the space grid structure,the accidents are also more and more.So far,the analytic method of long-span spatial structures can be induced into two models: segment analysis of top and bottom structure and global analysis of whole structure.Both analytic methods can not leave out the boundary condition of bearing,which has an influence on computing results.The indistinct designing theories and unreasonable structures make the design and structure fall short of computational assumption,causing hidden danger.Thus,the influencing regular and level of boundary condition on computing results and a reliable calculating method are expected to be researched.The precise method to determine stiffness and the difference degree of simplified value and precise value are expected to be founded to guide the calculation.Some achievements are as follows:(1)The static loading test and simulating computation of space grid structure are conducted.Testing data satisfied computation results and the code,which validated the reliability of simulation.(2)From the beginning of calculating flow of space structures,the design analysis methods of long-span spatial structures and the existing problems of software of space structures were summarized,which confirmed the influencing factors of bearing design.Different bearing stiffness of top models with various span were selected to stimulate and compare,which ensures the influences from different stiffness on computing results.(3)Combined with the research achievements of traditional bearing and analytic results of bearing stiffness,a new bearing model was explored,pointing at the defect that existing bearings can not consider the secondary moment,which is called damping semi-rigid pin bearing.This new bearing can resist secondary moment in a certain extent and precisely control moment through the instrument reading in that extent.After the moment excesses ultimate bearing capacity,the new bearing can be rotated to release moment and protect constructional element.After overload appears,the whole structure can be recovered to the original working state by replacing the moment resisting device.We has designed the structure of this bearing and elaborated the constructional requirements,working mechanisms and destroy forms of this bearing,which provides the reliable basis of research and application.