ABSTRACT
I. Introduction ...................................................................................................................... 280
A. The Importance of Noise and Vibration.................................................................. 280
B. Basics of Acoustics .................................................................................................. 280
C. Sources of Railway Noise and Vibration ................................................................ 282
II. Rolling Noise ................................................................................................................... 282
A. Mechanism of Rolling Noise Generation ................................................................ 282
B. Surface Roughness ................................................................................................... 283
C. Wheel Dynamics ...................................................................................................... 285
D. Track Dynamics ....................................................................................................... 287
E. Wheel-Rail Interaction ........................................................................................... 288
F. Noise Radiation........................................................................................................ 289
G. Computer Packages.................................................................................................. 290
III. Reducing Rolling Noise................................................................................................... 290
A. Controlling Surface Roughness ............................................................................... 291
B. Wheel-Based Solutions ............................................................................................ 291
1. Wheel Damping................................................................................................. 291
2. Wheel Design .................................................................................................... 292
C. Track-Based Solutions ............................................................................................. 293
1. Low Noise Track............................................................................................... 293
2. Slab Tracks ........................................................................................................ 294
D. Local Shielding and Barriers ................................................................................... 295
IV. Impact Noise .................................................................................................................... 296
A. Introduction .............................................................................................................. 296
B. Wheel Flats .............................................................................................................. 296
C. Predicting Impact Noise from Wheel Flats ............................................................. 298
D. Rail Joints................................................................................................................. 299
E. Reducing Impact Noise............................................................................................ 301
V. Curve Squeal .................................................................................................................... 301
A. Mechanism of Squeal Noise Generation ................................................................. 301
B. Reducing Squeal Noise ............................................................................................ 303
VI. Other Sources of Noise .................................................................................................... 304
A. Aerodynamic Noise.................................................................................................. 304
B. Power Unit Noise ..................................................................................................... 304
VII. Vehicle Interior Noise...................................................................................................... 304
A. Vehicle Interior Noise Levels.................................................................................. 304
B. Measurement Quantities for Interior Noise............................................................. 305
C. Airborne Transmission............................................................................................. 307
D. Structure-Borne Transmission ................................................................................. 308
E. Prediction of Interior Noise ..................................................................................... 310
VIII. Ground-Borne Vibration and Noise................................................................................. 310
A. Overview of Vibration Phenomena ......................................................................... 310
B. Surface Vibration Propagation................................................................................. 311
C. Tunnel Vibration ...................................................................................................... 315
D. Vibration Isolating Tracks ....................................................................................... 317
E. Summary .................................................................................................................. 319
IX. Vibration Comfort on Trains ........................................................................................... 320
A. Introduction .............................................................................................................. 320
B. Assessment of Vibration Comfort in Trains ........................................................... 320
C. Effects of Vehicle Design ........................................................................................ 321
References..................................................................................................................................... 322
Environmental noise is an issue that has seen increased awareness in recent years. Within the
European Union (E.U.) it is estimated
that 20% of the population live in areas with unacceptable
noise levels.
