Abstract: The exterior noise of high-speed trains varies according to different forms of high-speed railway lines. In order to study the difference of the two main types of lines, namely bridges and embankments, on the characteristics of external noise of high-speed trains, referred to the ISO 3095 standard, based on the anti-convolution beam-forming algorithm, a microphone array with 78 channels is used to identify external sources of high-speed trains experimentally. The pass-by noise of high-speed train are measured by free-filed microphone. Through noise tests, the exterior noise characteristics of high-speed trains in two types of lines under different speeds are compared and analyzed. The results show that under the same operating conditions, the pass-by noise of high-speed train running on the embankment section is 0.1 dBA to 1.8 dBA higher than that of the bridge section, and this difference will enlarge with the increase of train running speed. According to the distribution characteristics of sound sources of the vehicle, the noise in the pantograph area of the high-speed train is most significant in the bridge section or the embankment section when train running at a speed of 300 km/h, followed by the bogie area. When the train runs on the bridge section, the bogie area noise is slightly higher than the embankment section, which may be related to the overall stiffness of the track of bridge section. During the train operation on the embankment section, the noise on the surface of the train body is greater, which may result in the ground reflection in the embankment section. With the increase of speed, the difference between the pantograph noise at the two types of lines gradually becomes smaller, while their difference between the bogie area noise at the two types of lines remains basically unchanged.

Key words: high-speed trains, external noise, source identification, pass-by noise, bridge, embankment