Properties Research On A Large Annular Stadium Roof Structure With Cantilever Beam String

The stadium roof structures are limited on many aspects, such as structure disposal, architecture form and so on. The hybrid structure made up of tendons, struts and beams is a very active structure system. According to the system's characters, a kind of stadium roof structure that harmonized with environment and function can be constructed. It is significant to study the structure deeply.The paper presented a large annular cantilever beam string stadium roof structure using the theory of beam string structure. The stadium roof structure is a novel structure that is reasonable in bearing force by using the character of the tendon and beam fully. The struts in the structure avoided enduring big moment, moreover the pre-stress upper chord tendon and the annular beam work together to resist upward and downward load, as embody the structure's artifice and wonderful space mechanical property.The paper discussed the calculation methods of tendon. Using the thought of moment distribution, the paper presented a simplified and fast numerical method -Tension Distributing Method (TDM). This method had the characters of clear concept and convenient computation. Comparing with frozen-heated method, the method needed not calculate β and the distributing coefficients were clear. It was shown that the results of the paper were consistent with those of frozen-heated method.Through the nonlinear analysis of the large annular cantilever beam string stadium roof structure, it was shown that the structure had the strong performance of resisting uniform load and dissymmetry load. By the geometry parameters analysis, it was pointed that the distance between the outside annular and the most outside annular should be required to ensure the structure's stiffness; with the increase of height H between the inside annular and outside curve equation, the stiffness would be enhanced; when the H became very big, the structure presented the linear character, so the structure wasn't easy to yield; the sizes of long axis and short axis had the important influence to the structure's nonlinear performances and with the increase of span; the structure presented the strong nonlinear character, contrarily the structure presented the linear character.Through the dynamic character analysis of the large annular cantilever beam string stadium roof structure, it was obtained that the stiffness of the structure was between the stiff structure and flexible structure and the frequencies were dense, vertical vibration was dominant and then the string beam's lateral vibration and torsion vibration.From the results, it could be known that the structure's dynamic displacements were related with the seismic waves dimension and direction. When X direction seismic waves were input, the Y direction dynamic displacements on the symmetry surface were nearly zero. But when threedirections seismic waves were input, the Y direction dynamic displacements on the symmetry surface increased rapidly to the same grade of X direction. So the three directions seismic waves were necessary for the dynamic analysis of the structures. From the graph of time-history, it was known that the influence of phase difference was apparent, and should be calculated. The initial pre-stress variation in structure had no heavy influence.Applying the tool of the wavelet theory, the complex loading signal was composed to the simple loading signal and was used in dynamic stability analysis. It was shown that there were catastrophe skip phenomena and repetitive instability phenomena in the analysis of the dynamic stability of the Gerdesker doom latticed shell. The loading-displacement curve was consistent with the loading-energy curve, and the both could explain the whole dynamic course and the phenomena of dynamic instability. The courses of structures vibrations and dynamic instabilities were a process of energy deposition, release and transfer. The structure stiffness influenced its dynamic stability properties. It was also shown that the displacements in the short axis augme...