A study on the dynamic characteristics and ultimate capacity of steel transmission towers

Abstract

The safety of steel towers strongly influences the reliability of power supply in transmission lines. The dynamic characteristics, non-linear behavior, and ultimate capacity of 345 kV steel transmission towers are mainly studied in this article. The approach in this article is based on the ensemble empirical mode decomposition method, the down-sampling process, and the Hilbert–Huang transform. This study intends to identify vibration characteristics and detect damage from the measured ambient vibration data. Two different types of tower used by Taiwan Power Company (TPC), suspension towers (Type B) and strain towers (Type E), are discussed in this study. According to the specifications of the TPC Standard Code, the applied loads on a tower in the transverse, longitudinal, and vertical directions are determined, and the applied forces are increased gradually until the tower fails. Finally, the ultimate capacity for the tower are found by using the stiffness matrix operation approach dealing with non-linear behavior. The results of this study will be a valuable reference for advanced studies and for improving the design of steel transmission towers in Taiwan.