Curve squeal of urban rolling stock—Part 2: Parametric study on a 1/4 scale test rig

This paper is the second of a series of three, dealing with curve squeal of urban rolling stock such as metros and tramways. Measurements were carried out on a 1/4 scale test rig; they include parametric variations on a mono-block wheelset, and tests of anti-squealing solutions. The parametric variations show little influence of load and lateral contact position, except in the case of contact between the wheel flange and the rail, which prevents squealing. A relation between noise level and two kinematic parameters, rolling speed and angle of attack, is confirmed experimentally. The test of solutions leads to the determination of the damping value of the main wheel mode which is needed to suppress curve squeal. The average friction coefficient as a function of lateral creep is measured in dry conditions and with water.