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百度连英文都不行吗
Dynamic train–track interaction in turnouts is far more complex than on ordinary tangent or curved tracks. Large wheelset displacements and multiple wheel–rail contacts are common. Severe impact loads with significant contributions from high-frequency dynamic interaction are generated, when nominal wheel–rail contact conditions are disturbed at various locations in the turnout. The largest disturbances occur when the wheels are transferred from stock rail to switch rail in the switch panel and in the crossing panel when the wheels pass the gap between wing rail and nose rail. Due to wear and plastic deformation, surface irregularities with wavelengths of 1–10 cm may be present on the running surfaces of wheels and rails. This calls for models of train and turnout that are valid in a wide frequency range up to about 1 kHz. In addition, the assembled model needs to account for vehicle dynamics at low frequencies due to nominal turnout geometry and track irregularities with wavelengths in the order of 1 m.