Study On Dynamic Stability Of Geodesic Single-layer Spherical Reticulated Shells

At present, dynamic stability analysis of Kiewitt single-layer sphericalreticulated shells is emphasized, but dynamic stability analysis of geodesicsingle-layer spherical reticulated shells is scare. Therefore, the dynamic stability ofgeodesic single-layer spherical reticulated shells are discussed in this dissertation, andthe main contents and achievements are shown as follows:1. It is researched that the geometry specialty of geodesic single-layer sphericalreticulated shells, then the corresponding macro is work out and the parameterizedmodel of single-layer reticulated shells is realized.2. The free vibration characteristics of geodesic single-layer spherical reticulatedshells are analyzed considering the influence of some factors such as the span, theratio of rise to span, the roof load, the size of grid and the condition of supports, thenthe first frequency practicality designing charts are drawn.3. The dynamic stability of geodesic single-layer spherical reticulated shellsunder the simple loads is analyzed based on the time-history analysis method. Wheninvestigating the stability of the shells under step loads, the geometric imperfectionand the structural damping are taken into account and the relationship of geodesicreticulated shells under step loads and static loads is discussed. Harmonic responseon the shells is analyzed to determine the resonant frequency of the shells, and thedynamic stabilities of the resonance region and off resonance region of shells underharmonic load are analyzed respectively. The dynamic stability of shells undertriangle load is analyzed with the influence of the duration taken into account.4. The dynamic stability of geodesic single-layer spherical reticulated shellsunder the seismic excitations are analyzed based on the time-history analysis method.The influence of factors to the response behaviors, such as the input dimensions ofthe seismic excitations, the material nonlinearity, the structural damping, the initialgeometric imperfection, the ratios of rise to span, the sizes of grids, the roof loads,the different earthquake waves and the condition of supports, are discussed. The research results of this dissertation are not only the perfecting calculationtheory of single-layer spherical reticulated shells, but also a good reference for actualproject designing and a theoretical foundation to compile the relevant designcriterion.