Structural Performance Analysis Of 3D Parking Garage Considering Diaphragm Effect

With the rapid development of the national economy and automobile industry,the popularity of household cars has been improved several times in China.However,the growth of city parking facilities is far behind that of vehicles,especially in the highly energetic and prosperous downtown,which makes the annoying parking problem an urgent issue to be solved.As a new form of parking,the 3D-parking structure has become the priority to solve the parking problem in metropolitan area because of its land-saving,high-efficiency and security.In general,the 3D-parking structure with large height-width ratio,has no infill walls and floor slabs,which makes it a typical ‘tall and slender' structure with a risk of overall instability and overall overturning.All the above structure features and load features make the mechanical characteristics and design method of 3D parking structure different from these of the ordinary housing steel structure.Therefore,the targeted research on the static and dynamic performance of tridimensional parking structure combined with its structure and load features has important theoretical and realistic significance.The proposed diaphragm effect of the enclosure structure on the lateral stiffness of the tridimensional parking structure is considered.Firstly,based on existing diaphragm theory and test data of fasteners,a simplified simulated method of diaphragm effect is introduced.Then,a model in which diaphragm effect on the static properties of the 3D parking structure is considered,is simulated by ANSYS finite element software in this thesis.The change of mechanical characteristics of the structure under the action of lateral load is studied when considering diaphragm effect,and compare it with the structure that not considering the diaphragm effect.Then the influence of the layout parameters,such as arrangement of fasteners,purlins and sheetings,of the profiled sheet on the lateral stiffness of the structure is considered,and the stress distribution and stress mechanism of the profiled plate are studied.Aimed at the 3D parking structure of different heights,the effect of the braces on the lateral stiffness of the structure is studied,and the reasonable brace arrangement is discussed when considering the diaphragm effect.At last,a simplified method that a single diaphragm profiled sheet is replaced with a strut and tie model,is introduced when considering the computing power and calculation time limit of the computer.By contrasting with the result of the detailed model,the accuracy of the simplified method is verified.Then the seismic performance of the simplified finite element model of the structure is discussed,the seismic response of the overall structure and the influence of the diaphragm effect is studied.The research in this thesis could provide theoretical basis and reference for the practical engineering application of the 3D parking structure.