Dynamic Behavior of Lattice Transmission Towers

Transmission towers as kind of complex structures are comprehensively used in power transmission lines. Regarding the exposure of transmission towers to the wind and storm, the dynamic investigation of these structures is important. In this research, the dynamic behavior of a lattice transmission tower, including nonlinear effects i.e., geometric, material and joint slippage, is studied. For this reason, the lattice transmission tower is firstly pre-analyzed due to the weight load, incorporating nonlinear parameters in different cases, and then, the frequency analysis is performed and the natural frequencies of the lattice transmission tower are obtained. Afterwards, these natural frequencies are compared for different cases and it is observed that in contrast to the geometric and material nonlinearities which are not effective on the natural frequencies of the structure, incorporating the joint slippage can substantially decrease the natural frequencies. These natural frequencies are significant in the dynamic analysis of these structures either individually or as coupled system along with conductors. Finally, the first five mode shapes of the tower are presented

Keywords:

lattice transmission tower , nonlinear effects , joint slip effect , NASTower , natural frequency