Free Viboration And Earthquake Response Analysis Of Space Grid Structure

Space grid is a sort of preferable roof type for long span buildings. It has the 3D transfer mode of force, save steel material, large rigidity, small building height, industrialized,constructed process, and beauty architectural sculpt. With the development of the economy and constant progress of science and technology, application of grid structures in buildings is more and more extensive. However, as earthquake disaster happen very frequently in recent years, how to perform seismic design of space grids becomes an important problem concerned. So it's necessary to do some research and analysis for the response of space grid structure and the conclusions can be used as references for engineering practice.In this paper, the mainly research is made up of four parts hereinafter.At first, the finite element theory, functions of ANSYS software and typical analysis process are briefly introduced. Commonly principle of ensuring geometry parameter of space grids finite element model are given, the ANSYS is adopted to establish the space grids finite element model.In this ANSYS model, the element of LINK8 is used to simulate the element of pole. Comparison analysis between《code》method and ANSYS analysis method is carried out, and the results prove that the space grid finite model by using ANSYS is correct.Secondly, the analysis process of the free vibration of space grid structure by using the ANSYS is introduced. Manifold space grid finite element model are established and their free vibration calculation are finished, the general rule of space grid structure is achieved and influence factors for space grid structure are discussed,and the influence factors of different lord,boundary condition and different span are studied.Thirdly, the procedures of spectrum analysis by using the ANSYS are presented. Three space grid structures having different spans are analysed, the distribution rule of internal force of space grid under vertical earthquake and horizontal earthquake, and comparison analyze their. And the influence of span on the internal force and the display of space grid are studied.At last, the nonlinear performance of space grid structure is analyzed by using time history method. The results of linear analysis and nonlinear analysis are compared. Some suggestions are put forward. And the seismic responsibility result of different seismic wave is achieved also.