Numerical computation of dropper stress and fatigue life in a catenary system under fluctuating wind load

In this paper, numerical computation of dropper stress and fatigue life in a catenary system under fluctuating wind load is performed. We take contact wire as a beam element and obtain the response equation under the action of moving load and fluctuating wind load. Thus, we determine the initial boundary value conditions of the vibration equation of the dropper and calculate dropper stress and fatigue life under different conditions. The results show that when contact wire is subjected to fluctuating wind load with a constant wind attack angle, the higher the wind speed, the more serious the fatigue damage caused by fluctuating wind to the dropper. When the wind speed is constant, the smaller the wind attack angle is, the smaller the adverse effects of fluctuating wind on the dropper are. Under the fluctuating wind, fixed wind attack angle and wind speed, the higher the amplitude of the sinusoidal force is, the more likely the dropper is to break, and dropper IV is more sensitive to the amplitude increase. Under the conditions of different wind speeds, attack angles, and amplitudes, dropper IV is most likely to break. This work is helpful to analyze the train safety problems caused by droppers, so as to reduce the safety risks.