| A finite element model of a five-span transmission line section was established by ANSYS with a popular tower as a prototype, then the dynamic characteristics of transmission line system, static response when icing, ice-shedding and wire-breaking problem were studied wholly. A form-finding method based on static equilibrium was proposed while solving the form-finding problems in cables by nonlinear finite element method. For simple cable structure, this method is easy and effective when several form-finding scenarios were completed. The dynamic characteristics of a single tower, cables and tower-line system were analyzed, and the local mode of the tower doesn't appear too early by adding subsidiary bars when analyzing the mode of the tower. The static effect of the ice thickness, the span length, the unequal spans and the unequal elevation at the span ends on the transmission line system was analyzed. Then, towers and cables were modeled together and separately, to analyze the coupled response between towers and cables by the same ice-shedding scenario. For the model used, the results show that the influence towers have on cables can be neglected in the dynamic analysis, but the influence cables have on towers is remarkable. The dynamic response of tower-line system was analyzed by different scenarios. It proved that the dynamic effect when ice-shedding can't be ignored. Finally, the wire-breaking was studied, and the displacement and internal force of the tower adjacent to the wire-breaking span were analyzed.
|
PDF Full Text Request