Analysis of catenary positive feeder galloping mechanism in strong wind section based on fluid-structure interaction

Abstract:

To better understand the mechanism of impact of windbreak wall wake on the galloping of catenary positive feeder, this study establishes an analysis model for wind-induced vibration response of positive feeder in light of the aerodynamic theory, focusing on the positive feeder of LanzhouUrumqi high speed railway. The fluid-structure interaction method is used to analyze the time history of two-dimensional models with different natural freguency rations and degrees of freedom. The results show that both the degree of freedom and the frequency ratio significantly impact the galloping amplitude of the positive feeder. A lower frequency ratio amplifies the impact of wind speed on the amplitude of the positive feeder and extends the range of wind speeds triggering the galloping of the positive feeder. The galloping amplitude of the positive feeder in the vertical single-degree-of-freedom system is greater than that in the vertical-horizontal two-degree-of-freedom system, indicating that the horizontal vibration of the positive feeder has a certain limiting effect on the vertical vibration. When the positive feeder vibrates in the wake of windbreak wall, the windward angle of the positive feeder is constantly changing. A larger windward angle is more likely to induce substantial galloping of the positive feeder. The galloping mode of the positive feeder of the catenary in the strong wind section is determined as Den Hartog galloping without icing. The research results offer a deeper understanding of the galloping mechanism of the positive feeder under the condition without icing in the strong wind section, providing theoretical insights into mitigating and controlling the galloping of the positive feeder of the catenary.