Shape Analysis, Dynamic Properties Study And Static And Dynamic Field Tests Of Suspendome Structure

Suspendome is a new kind of hybrid structural system, which bases on the tensegrity system and single-layer reticulated dome. It can cross a larger span economically and reasonably with advantages of high rigidity, high stability and simple joint construction. Based on previous research work, the shape determination of suspendome, designing principle of hoop cables' prestress, dynamic characteristics, static and dynamic field tests are further studied systematically and comprehensively in this paper. First, nonlinear finite element method is introduced and calculation model of cable elements is emphasized. The author also suggests to simulate cable elements with linear elements through two nodes.After summarizing the general contents about shape analysis, this paper points out the speciality of shape analysis of suspendome and gives the definitions of zero state, prestress balance state and loading state. Taking initial strain as medium, a program in APDL program language running in ANSYS program on tension compensation method and athwart-iteration method is developed, which may successfully get the geometry of zero state from prestress balance state. This accurate calculation model can lay a foundation for the next work. The basic formulas which can determine the ratio of each hoop cable's prestress are derived. The method and steps to determine hoop cables' prestress level are proposed with a aim of reducing stresses in outer ring girders to zero. Then a program in APDL program language running in ANSYS program is developed. The natural vibration characteristics are studied through modal analysis and time-history analysis. The influence of loads, rise, span, prestress and support on structural mechanical behaviors is also researched.The static and dynamic field tests on suspendome are carried out. Loads are loaded step by step on two different structures respectively, and strains of elements and displacements of nodes are measured in static tests. Vibration tests are carried out respectively in two periods of roof's building. Narrowing the range of the natural frequencies with Ambient Excitation Method and measure natural vibration frequencies and vibration modals with Hammer Exciting Method. A comparison of results between test and analysis is mentioned.