Theoretical And Experimental Research Of Suspen-Dome Structures

Suspen-dome is a kind of large-span prestressed hybrid structure, consisting of an upper single-layer lattice shell and a lower cable-strut system. Due to its better overall stability performance, and relatively easier construction, suspen-dome has a very extensive application prospects. In order to promote more extensive application, systematical research of this structure were presented from the aspects of the form and classification, morphology analysis, static and dynamic analysis, stability, construction analysis and model experiment.First ,the forms of this structure were summarized, and some improvement and innovation of its lower cable-strut system arrangements were made, then 16 sorts of cable-strut system arrangements were presented. Based on the different known state parameters, it presented three possible categories (totally 11 cases) of morphology analysis. Moreover, the corresponding iterative algorithms and calculation processes were given. At the same time the theory of morphology is applied in the prestress design and model modification, which belong to morphological analysis category. The research indicated that force finding of suspen-dome must be carried out in the processes of the analysis.The static ,dynamic and stability performance of 9 different forms of suspen-domes and the corresponding single-layer lattice shell were analyzed and compared. The results indicated that the lower cable-strut system can improve the static performance and stability of single-layer lattice shell obviously, and reduce the structure sensitivity to its support's radial stiffness. When the cylinder number of cable-strut are certain, arrangement of radial cables have less effects on structural static response and stability. However, when rib type or partial rib type is included in cable-strut system, local vibration occurs in cable-strut system. The obtained conclusions are very helpful to guide the design of cable-strut system.The effect of the distribution and magnitude of initial geometric imperfections on overall stability were studied in detail. It is suggested that the first antisymmetry buckling mode should be chosen as initial geometric imperfections, and the magnitude of initial geometric imperfections should be between 1/500 and 1/300 span ,when uniform imperfection method is used for stability calculation.When the needed initial strains of the lower cable-strut system at zero state are fixed, the length of the element in cable-strut system at initial state and at zero state are also determined, based on which , the positive direction construction simulation method is presented. It can be used to simulate different construction schemes. At the same time, some problems during tension were studied in detail, for example, struts slope, tension friction and the selection of geometry configuration at zero state. Moreover, that tension by radial cables is best construction scheme is indicated.A scaled model structure with the span of 8m was made according to practical structure. Structural constructions under 6 sorts of construction schemes, structural static performance under 3 sorts of load cases, structural dynamic performance under 2 cases were studied. It is indicated that the calculation theory is accurate by the results of the static and dynamic tests. It was drawn that half span load should be carried out as control load in practical design cases, and too much local loads should be avoided in practical construction. From the results of the tension tests, it is illustrated that the presented construction simulation method can be used to simulate construction accurately. Moreover, the structural static response during tension basically according to linear principle of superposition was tested.