Efficient Flow-Induced Vibration Analysis of a High-Speed Pantograph Using a Dynamic-Stiffness-Based Flexible Model Driven by IDDES Aerodynamic Loads

Flow-induced vibration of high-speed pantographs becomes increasingly important as train speed approaches and exceeds 400 km/h. This paper develops an efficient computational framework that couples component-resolved unsteady aerodynamic loads from improved delayed detached eddy simulation (IDDES) with a dynamic-stiffness-method (DSM) flexible model of a high-speed pantograph. Two operating orientations, namely, knuckle-downstream and knuckle-upstream, are compared at 400 km/h, and the more unfavorable knuckle-upstream orientation is further investigated over 400km/h–600km/h. The DSM model contains 49 beam elements and 42 nodes and shows good agreement with a refined three-dimensional solid-element finite element model in the low-order frequency range. For a 2 s transient analysis, the proposed model predicts the panhead displacement response with peak errors below 5% relative to the finite element model while reducing the computational time from 53 min 22 s to 35 s on the same platform. The results show that vertical vibration dominates the structural response, with the panhead peak vertical displacement reaching about 20 mm in the studied 400 km/h open-line case. Frequency-domain inspection of the panhead aerodynamic lift and vertical displacement shows that broadband aerodynamic excitation mainly activates the low-order structural modes, with a low-frequency aerodynamic component around 3Hz–4Hz and additional energy mainly over the 20Hz–30Hz range. The knuckle-upstream orientation increases the standard deviation of the equivalent contact-force response by 46% compared with the knuckle-downstream orientation at 400 km/h. For the knuckle-upstream orientation, increasing speed from 400 km/h to 600 km/h raises the standard deviation by 189%. The proposed framework provides an efficient tool for rapid comparative evaluation of pantograph flow-induced vibration under multiple operating conditions.