New Approaches for Design and Experimental Analysis of Damping Ring and Its Influence on Railway Wheel Dynamics

This paper deals with the optimization of BONASILENCE damping ring inserted into a groove on a monoblock railway wheel to suppress radial and axial mode shapes of vibrations that cause rolling and curve squeal noise. A free open-ended damping ring has a slightly larger diameter than the groove and, when inserted, pre-stress of the ring is assured. However, when the circular ring of larger diameter is inserted into a smaller circular groove, the deformation of the ring is such that the ring and groove are not in contact along the entire circumference. Therefore, a noncircular shape of the free damping ring modeled by beam theory for providing even pressure distribution between the ring and groove along the entire circumference is under development. For evaluation of the damping ring effect on different circumferential pre-stresses, a new approach of measurement of slip between the ring and the groove based on the optical correlation method was used. Patches of speckle images with stochastic structure were generated and glued on the ring and the rim on their boundary at the places of presumed maximal wheel vibration. Vibration of the wheel was then excited, and the area of speckle images was recorded by a high-speed camera. Then the local relative motion between the ring and the wheel which is in the range of micrometers and up to 2 kHz of vibration frequency was evaluated. This method can be used for the finding of an optimal setting of the pre-stresses in the damping ring to achieve the maximal damping.