Study On Static And Dynamic Behavior Of The Bird-Nest-Patterned Grid Structrue

The bird-nest-patterned stadium is the successful bid scheme for 2008 Olympic Games in Peking. The major structure of its roof is an elliptic plane grid structure which consists of several plane trusses irregularly crossed in two directions. Each truss is tangential or tangential approximately to the internal ring. It is thus named as a bird-nest-patterned grid structure. Up to now, no studies on this type of structure have been carried out at home and abroad. Thus, it is important to study the structural performances in theory and engineering.In this paper a circular bird-nest-patterned grid structure consists of some identical plane trusses is first investigated in the aspects of form and load behavior. Then the simplified calculation method for such structures with special boundary condition is proposed. Using the simplified method and derived formula, the internal force of each bar and displacement of each node can be obtained conveniently.Circular bird-nest-patterned grid structure is discussed about its static behavior when acted by .vertical loads. The internal force of bar and displacement of node are studied. The distributing of internal force and vertical displacement of truss node is analyzed. In order to roundly analyze the mechanical property, its internal force and displacement is discussed systematically.The vibration characteristic of certain model is analyzed. Frequency, vibration shapes and stiffness distributing of the structure are find out. The influence on vibration characteristic acted by difference including boundary constrain and different form is studied..Vibration shapes-separation-spectra-method is adopted to analyze the dynamics behavior of circular bird-nest-patterned grid structure under the common earthquake, The law of dynamic, internal force is obtained. The step-by-step integration procedure is adopted to analyze the dynamic response of circular bird-nest-patterned grid structure under common earthquake, compared with analysis result by Vibration shapes-separation-spectra-method, the conclusion that time-history method should be adopted to analyze dynamic characteristic of this structure is obtained.Finally, some conclusions are summarized and the topics for further research are put forward to.