Optimization of resilient wheels for rolling noise control

Resilient wheels are currently used on light rail systems such as tramways to prevent squealing noise and to reduce impact noise. On the other hand, t hey are rarely found on main lines (passenger rolling stock and freight rol ling stock). Although manufacturers often claim that resilient wheels are f avourable for rolling noise control, no extensive theoretical investigation confirming this statement has been published to date. In this paper, it is shown how resilient wheels can be effectively optimised in order to reduce rolling noise emission, compared to a conventional monobloc wheel. A preli minary analysis of the physical phenomena accounting for rolling noise gene ration emphasizes the key design parameters affecting both wheel and radiat ion. These parameters are the radial dynamic stiffness and damping loss fac tor of the rubber layer. The tread mass is also relevant. The influence of these design parameters is then qualified by a parametric study performed w ith the TWINS software. An optimum radial dynamic stiffness of the resilien t layer is found which depends on operating conditions. Reductions in overa ll rolling noise up to 3 dB (A) are calculated for the configurations inves tigated. However, poor selection of the design parameters can lead to a noi se increase compared to a standard monobloc wheel. It is also shown that a proper design for rolling noise control will not affect wheel efficiency wi th regard to squeal noise. (C) 2000 Academic Press.