Testing the Loading of Bearing Rings with Surface Waves Using Acoustoelasticity Effect

Abstract

The results of experimental studies of a nondestructive testing method for assessing the loading of bearing rings on an axle journal using the acoustoelasticity effect based on measuring the characteristics of elastic surface waves are presented. Reference blocks for loading with a difference in pilot diameters in the range from 38 to 119 $\mu {\text{m}}$ with an error of no more than 7 µm have been developed and manufactured. A hydraulic testing bench for mechanical loading of bearing rings simulating their press fitting on an axle with loading of up to 46 microns was certified. The acoustoelastic coefficients $\alpha = (5.48 \pm 0.14)$ ${\text{TP}}{{{\text{a}}}^{{-1}}}$ were experimentally determined for surface waves in steel ShKh15 based on the delay in the time of recording pulses that repeatedly (2–5 times) circled the ring. The correlation method is optimized for determining the delay time of a wave in a loaded ring relative to an unloaded one according to the condition of minimizing the uncertainty associated with a change in the pulse shape. The main reasons for errors and uncertainties in measuring the absolute time of propagation of a surface wave are established: the effect of waves reflected from the boundaries, surface curvature, and attenuation. The bearing rings loading was measured on loading reference blocks using the acoustoelasticity effect, and the estimation of the stress measurement uncertainty was made.