Static And Dynamic Analysis On A Double Circuit Intermediate Tower Consisted Of Steel Tubes And Angel Steels

Transmission towers are important lifeline systems, so it's very important to study the influence regularities caused by ground deformation, wind and earthquake. In the past few years, some transmission towers have been damaged or destroyed, which had led to great loss of people's life and property. So high accurate analysis on transmission towers is very necessary. Steel tube towers are more widely used. Double circuit intermediate tower consisted of steel tubes and angel steels is rarely studied at home and abroad. It is very necessary to study static and dynamic characteristics of this kind of tower. Some conclusions are shown as follows:Results of geometric nonlinearity show that geometric nonlinearity has a little influence on the design and analysis of the tower. It's not necessary to consider the influence caused by geometric nonlinearity. At present, CAD software for tower structures is not suitable for the analysis on the ultimate load capacity. However, the ultimate load capacity can be calculated by using general software ANSYS. Several wind load cases have been considered in this paper. Transmission towers are usually erected in remote mountainous areas. Uneven foundation subsidence of transmission towers should be prevented. The transmission tower in subsidence area was analyzed by numerical method, and the influence regularities of ground deformation on internal force and structure deformation of the tower were studied. Results show that the worst condition is that one support sinks.Modal analysis is the basis of all dynamic analysis. Natural frequencies and modes of vibration are obtained by using tower-mass modal. On the basis of the modal analysis, the conventional seismic response spectrum method is adopted to obtain the seismic response of the transmission tower when the incident angles of earthquake waves are different. Results show that incident angles of earthquake waves impact a lot on the tower. The maximum value of the bars doesn't come up in a same excited direction. Then taking time-procedure method and using general software ANSYS, earthquake resistance of the tower is analyzed when the dimensions of earthquake waves are different. Contrasts of displacements of suspension point of conducting and ground wires between one dimension and three dimensions of earthquake waves, contrasts of displacements between two dimensions and three dimensions, and spectrum analysis of earthquake waves using Fourier transform. Analysis of wind-induced vibration response is another aspect of dynamic analysis, by adopting Davenport Spectrum, wind velocity time history on structure was simulated by Matlab 6.5. Response of transmission tower was studied by using general software ANSYS. Results are shown as follows:bearing capacity of foundation is not enough by adopting usual method; Stiffness of the changing slope should be carefully considered during the process of design, reaction of tower caused by shock wave is more serious.