A HYBRID MODEL FOR THE NOISE GENERATION DUE TO RAILWAY WHEEL FLATS
✍ Scribed by T.X WU; D.J THOMPSON
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 574 KB
- Volume
- 251
- Category
- Article
- ISSN
- 0022-460X
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✦ Synopsis
A numerical model is developed to predict the wheel/rail dynamic interaction occurring due to excitation by wheel #ats. A relative displacement excitation is introduced between the wheel and rail that di!ers from the geometric form of the wheel #at due to the "nite curvature of the wheel. To allow for the non-linearity of the contact spring and the possibility of loss of contact between the wheel and the rail, a time-domain model is used to calculate the interaction force. This includes simpli"ed dynamic models of the wheel and the track. In order to predict the consequent noise radiation, the wheel/rail interaction force is transformed into the frequency domain and then converted back to an equivalent roughness spectrum. This spectrum is used as the input to a linear, frequency-domain model of wheel/rail interaction to predict the noise. The noise level due to wheel #at excitation is found to increase with the train speed < at a rate of about 20 log < whereas rolling noise due to roughness excitation generally increases at about 30 log <. For all speeds up to at least 200 km/h the noise from typical #ats exceeds that due to normal levels of roughness. When the wheel load is doubled the predicted impact noise increases by about 3 dB.