Model based sensitivity analysis of Leaky-Lamb wave propagation to the variation of viscous lubricant properties

The reliable operation of rolling bearings is basically determined by the permanent existence of lubricants to all contact surfaces. The outer ring of the bearing can be regarded as isotropic elastic material. At sufficiently large radii the outer ring can also be considered as a flat plate. In contrast, lubricants need to be considered as viscoelastic materials. The lubricant layer is in contact with one side of the outer ring of the bearing. In this contribution we investigate the sensitivity of Leaky-Lamb wave propagation to variation of the lubricants properties. Therefore an analytical model based on the well-known global matrix method [1] has been implemented. Simulations have been carried out with varying lubricant properties and varying lubricant layer thicknesses. We found the setup to be very sensitive to the lubricant's layer thickness if the spectral excitation of the waveguide covers the cut-off-frequency of the first higher order waveguide mode. This behavior has been confirmed in experimental studies.