Response characteristics for aeolian vibration of long-span conductors under local excitation

Aeolian vibrations often occur on transmission lines, which can result in fatigue damage to the conductors and metal fittings. In order to understand the mechanism of aeolian vibrations of long span conductors, a linear model of the forced vibration of finitely long damped tensioned strings under single-point harmonic excitation is established, and the corresponding Green's function solution of steady state response is derived. Based on the qualitative analysis of the parameters affecting the response type of the system, the discriminant parameter of the control response type and its expression are proposed. The spatial distribution characteristics and temporal and spatial evolution characteristics of wave responses under different discriminatory parameters are further analyzed. The relationship between the position of excitation and the amplitude of vibration wave is discussed. The results show that the discriminant parameter which determines whether the conductor acts like infinite conductor or not is the product nζ, where n is the mode number of the highest resonantly excited mode in the system. When nζ is small then single mode resonant response will dominate the total response. When nζ is large, except when excited near an end, the conductor can be considered to behave dynamically as if it were infinite in length. The excitation position has a significant effect on the amplitude of vibration wave. When the excitation position acts on the ideal peak of a certain vibration wave, the amplitude of the vibration wave is the largest, and when the excitation position acts on the ideal node position, it is difficult to form a significant vibration wave. The vibration wave of actual conductor is a mixed wave of standing wave and traveling wave. © 2021, Editorial Board of Journal of Vibration Engineering. All right reserved.