Theoretical And Experimental Research On Latticed Shell String Structure With Inner And Outer Truss Torus

A new type of spatial beam string structure(BSS), called latticed shell string structure with inner and outer truss torus, is proposed according to the roof of Yueqing Municipal Gymnasium. Compared with traditional radial BSS or suspendome, latticed shell string structure with inner and outer truss torus increase the visual ranges of rear seats in gymnasium. For a better understanding of mechanical properties and a promoting of the engineering application, the new structure is studied systematically from several aspects, such as shape determination, mechanical properties, stability analysis, seismic response and model experiment.Chapter I briefly summarizes the history and classifications of long-span spatial structures and reviews the development history, project applications and research status of BSS and annular tensile cable-truss structures. This new latticed shell string structure can be understanded from the above two structures. A brief introduction of the content of this paper is given.Chapter II summarizes the structure forms of latticed shell string structure with inner and outer truss torus. Six ways are given to classify this new type of structure, such as the relative position between the radial beams of latticed shell and radial cables, the grid form of latticed shell, radial beam curvatures of latticed shell, the cable forms, the strut arrangement and the inner hole covered by different space structures.Chapter III summarizes the shape determination methods of space structure and the shape determination problem of ribbed double inner and outer beam string structure is discussed. Based on the local analysis method and the nodal equilibrium equation, the simplified calculation method and computation table for initial prestress of ribbed latticed shell string structure is proposed. Numerical algorithm is introduced and some suggestions for improvement are put forward and the parameter selection of calculation processing is discussed. Two examples are investigated by the above two methods and the calculation results are compared. The results confirm the feasibility of two methods.Chapter IV studies systematically on static performances of the new latticed shell string structure. Ribbed annular space latticed shell string structure is taken as an example and its static behavior under full-span and half-span load is analyzed by ANSYS. Besides, the effects of prestress level and types of latticed shell are investigated.Chapter Ⅴ studies the stability of ribbed annular space latticed shell string structure systematically under full-span and half-span load. Besides, the effects of prestress level and types of latticed shell on the stability are investigated. The effect of initial imperfection on the stability are studied. The stability and economics of three types of latticed shell string structure, ribbed patterned, sunflower patterned and schwedler patterned, are studied.Chapter Ⅵ analyzes the dynamic properties and seismic behaviors of ribbed annular space latticed shell string structure. The modal analysis is carried out with the latticed shell string structure. The seismic response for the latticed shell string structure with inner and outer truss torus is studied subjected to El-Centro wave. Moreover, the effects of prestress level and types of latticed shell on vibration modes and seismic response are investigated.In Chapter Ⅶ, a1/15scale model of the roof of Yueqing Municipal Gymnasium was constructed. The experiment includes simulation of tension process, static loading, local cable broken and vibration characteristics. The experimental data measured and theoretical results are compared and analyzed.Chapter Ⅷ summarizes all the researches in this paper and lists some problems to be solved in the future for latticed shell string structure with inner and outer truss torus.