Modelling and mitigation of wheel squeal noise under friction modifiers

Abstract

The prediction of wheel squeal vibration and noise under the presence of friction modifiers is investigated using an efficient analytical model. The enhanced modelling is used to determine instantaneous rolling contact traction-creep curves from quasistatically measured ones using a two disk testrig under dry and friction modified conditions. The analytical solution is then compared with both numerical and experimental measurements of squeal vibrations and sound pressure level amplitude over a range of angle of attacks. Squeal is shown to occur in both the dry and friction modified conditions at about the same steady state amplitude. The robustness of the model is further verified under a much lower speed and the amplitudes, occurrence and non-occurrence of squeal is well predicted within measurement error. The model is shown to provide efficient quantified insight into why squeal noise may and may not occur under oil-based friction modification. Subsequently the model is used to determine an optimised region of the measured quasistatic traction-creep curve within which friction modification can eliminate wheel squeal.