Experimental study of dynamic bending stiffness of ACSR overhead conductors

Abstract

Abstract : Aeolian vibrations of transmission line conductors may cause fretting fatigue failure at or near the location of clamped devices. At these locations, the bending stiffness variation of the conductor has a large influence on its deformed shape and hence on its fatigue mechanics. Variable bending stiffness models could be integrated in non-linear finite element programs to obtain better mechanical behaviour predictions. However, there is very little data available in the literature to validate such numerical models. The objective of this paper is to present experimental data for the deformed shape of two types of ACSR conductors undergoing vibrations. The tests were performed on a 5.83 m test bench for various tensions, displacement amplitudes and frequencies. The displacement amplitude was measured at the vibration anti-node and at five locations near the squarefaced bushing. The results suggest a large stiffness variation near the bushing. This experimental study provides valuable data to compare with a numerical model of a vibrating conductor that includes variable bending stiffness.