Study On Dynamic Response Of Elliptical Parabolic Latticed Shells Under High-intensity Earthquake

Latticed shells have been widely used as they have excellent mechanics behavior and various kinds of Architectural style. Currently, the research of the latticed shells under dead load has obtained a series of results. However, the research of these structures under dynamical actions is still very insufficient. The core issue for research latticed shells dynamic response under High-intensity earthquake is that we will understand that changes in ductility of components and structures lead to the changes of structural performance ultimately.With the characteristics of complex structure, the huge of quantity of poles and nodes, people has made lots of studies about methods of modeling for reticulated dome and net cylindrical shell. According to the geometry characteristics of singer layer elliptical parabolic latticed shell, it is considered that elliptical parabolic latticed shell is replaced by surface formed by arc instead of parabola. The method applies the APDL (ANSYS Parametric Design Language) to program corresponding macro, and fulfils the speedy parameters modeling of singer layer elliptical parabolic latticed shell on the software of ANSYS. It is simple, fast and meeting the engineering requirements from examples proved.Natural frequency of singer layer elliptical parabolic latticed shell under some factors is studied by parameter analysis, such as different of span, loads on the roof, ratio of rise-span, division number and so on. Hundreds of calculation examples, the practical formula of the natural frequency for Single Layer Elliptical Parabolic Latticed Shell was proposed. In the comparison with the results of ANSYS, the proposed formula is accuracy and designers can hold up very quickly.Singer layer elliptical parabolic latticed shell has a good Elastic-plastic seismic behavior, so it allows some part of pipes into plastic-state without affecting bearing capacity of shells under seismic loads. The dynamic response of maximum pipe stress and displacement of node under combinations of vertical and horizontal earthquake actions is larger than individual effects under the horizontal and vertical earthquake. Therefor, it is reasonable that we must carry out combinations of vertical and horizontal earthquake actions when research the dynamic response of singer layer elliptical parabolic latticed shell.Isolation control analysis is carried out for single layer elliptical parabolic latticed shell in which all horizontal pin supports were replaced by spring supports or damped spring supports. For the isolated single layer elliptical parabolic latticed shell structure, its maximum horizontal displacement, the maximum horizontal displacement of isolators and the maximum reactions of supports are calculated under the action of rare earthquakes, respectively. The results have indicated that two kinds of the isolation devices can control the reactions of single layer elliptical parabolic latticed shell effectively. Damped spring supports can also reduce the displacements of the isolated supports and the displacements of the isolated shell significantly. Isolation is effective for reducing the vibration of large span shell.