Study on natural-frequency-based structural damage identification of steel transmission tower

The material theft of steel transmission towers has been an annoying problem in China, which often brings about severe accidents and imperils the entire power system. This paper deals with a feasibility study of utilizing natural frequencies in structural damage identification of steel transmission towers, which are three-dimensional spatial structures. On the basis of the finite element model of a 110 kV self-supporting steel transmission tower, the natural frequency variations between the intact and damaged states of the target transmission tower are analysed and compared. Finally, the influence of structural damage on natural frequencies is summarised, and the feasibility of real-time monitoring on transmission tower against steel theft is verified through some numerically simulated damage identification tests.