An acoustic model for stiffness measurement of tribological interface using ultrasound

This paper proposed an acoustic model represented by spring–damper elements connected in series for ultrasonic reflection at tribological interface. Tribological interface was treated as a thin layer of Maxwell material, so that the effect of ultrasound attenuation at interface can be simulated accurately. Then the acoustic model was obtained using asymptotic expansion of an exact solution for this interface layer. Finally, the feasibility of the proposed model for contact stiffness measurement was validated experimentally. The results demonstrate that the proposed model can provide a quantitative measurement for both dry interface and interface with liquid film.