Study on Force Calculation of Preformed Helical Fittings for Overhead Transmission Line

In recent years, the preformed helical fittings in several UHV transmission lines have been scattered, deviated and broken, which affects the safe operation of the whole overhead transmission line system. Therefore, it is necessary to study the fastening characteristics of preformed helical fittings and conductors or earthwires. In this paper, according to the fastening characteristics between performed armor rods and earthwire, the stress calculation of preformed helical fittings for transmission line is carried out. Based on the explicit solution method of quasi-static analysis, the performed armor rods and earthwire are modeled by finite element method, and the time step of load loading, the force of performed armor rods and earthwire system are analyzed by parametric design method. The calculation results show that with the increase of time step, the tension loading rate decreases gradually, and the dynamic effect of the system also decreases. The kinetic energy of the system and the ratio of kinetic energy to internal energy gradually decrease, and the decreasing range tends to be flat.