Abstract:

In order to consider random wind loads influence on the carbody structure fatigue strength, one typical carbody structure load spectrum calculation method is proposed here to study a high-speed train carbody structure based on wind-induced loads. The main contents include: According to the wind spectrum along the Beijing-Tianjin line, Cooper wind speed spectrum is chosen as the target spectrum to simulate the effect of wind speed on the vehicle based on linear filtering method (Kalman filtration method). At the same time, using the relationship between wind speed and air pressure, a method is used to obtain the unsteady aerodynamic loads of the high-speed train under cross wind based on weighting function. Vehicle multi-body dynamics model is created with vehicle dynamics parameters, Beijing-Tianjin intercity lines railway track irregularity and maximum instantaneous wind speed along the track line environment. And the typical vehicle operating conditions are also analyzed. As the aerodynamic loads are applied to the vehicle dynamics model, the running safety of high-speed train under the wind-induced loads is evaluated. According to the load spectrum simulation method proposed, the carbody structure load time histories are extracted. And load spectrums are compiled using rain-flow counting method. The results are shown that the linear filtering method can be used to obtain the wind speed power spectrum. And the target spectrum has high fitting precision during the main frequency ranges. The maximum wind speed spectrum energy are concentrated in 0.001-3 Hz. The aerodynamic calculation method by introducing weight function can be used to effectively filter the high frequency component and reflect the actual delay characteristic of aerodynamic loads. The results also illustrates the proposed method cab be used to study the typical carbody structure load spectrum under wind-induced loads.

Key words: aero-dynamic loads, finite element method, load spectrum, multi-body dynamics, carbody