Dynamic Analysis Under Strong Ground Motion On A Double-layer Flat Ellipsoid Reticulated Shell

Most of the buildings collapsed after Wenchuan earthquake that makes the seismic performance of buildings and areas fortification intensity become of great concern. A loud voice to improve the fortification intensity of the defensive zone. However, it is unrealistic to improve the defensive zone fortification intensity. But the security of some important’ building under the seismic over the region fortification intensity is the very issue to be considered.Reticulated shell structures are often as the roof of the important large-scale construction. Complex forms, a huge number of nodes and bars, and the study in the strong earthquake is very important.In order to verify the security of the reticulated shell under strong earthquake, this article make static analysis and dynamic analysis under strong ground motion on a double-layer flat ellipsoid reticulated shell in Shanxi Changzi County. The main research work and achievements include:1. Solid modeling of a whole shell in3D3S, analyze static mechanical properties of reticulated shells under29kinds conditions combination. Derive the worst operating condition combinations for the shell structure of this reticulated shell, and its control working conditions. Also found that the mechanical performance and regularity of the reticulated shell bar. And make some suggestions for some similar structure.2. Analyze natural vibration characteristics of the model in3D3S and SAP2000, by comparing the vibration period and frequency. Verify the correctness of the SAP2000analysis. Lay the foundation for the correct duration analysis. Also analyze and compare the natural vibration characteristics of the structure with different bearing. Get the natural vibration characteristics and vibration law of this structure from the analysis results. Summarizes the impact of the bearings on the vibration characteristics.3. The seismic fortification intensity of the project area for the6degrees. Using SAP2000simulate the time history analysis of structure under7degrees rare earthquake. Predict security of the structure. On the need whether to consider vertical seismic or seismic coupling structure, respectively the time history analysis of the structure in the horizontal seismic, vertical seismic earthquake and three directions earthquake. Structure in the event of7degrees rare earthquake is safe from the results of the analysis. It is also need to consider the impact of vertical seismic.