AN INERTIAL TRIBOMETER FOR MEASURING MICROSLIP DISSIPATION AT A SOLID-SOLID MULTICONTACT INTERFACE

An apparatus has been built to measure the shear response of a multico ntact interface between flat-ended solid bodies, rough at the micron s cale. The device makes use of inertia to apply a steady sinusoidal she ar force to a slider without direct mechanical drive. Both elastic com pliance and damping losses are deduced from the in-phase and out-of-ph ase components of the submicronic shear displacement. Operating freque ncies range between 15 Hz and 1 kHz, while below 100 Hz quasistatic mo tion of the slider is achieved. Acceleration amplitudes range typicall y between 0.1 and 7 m s(-2), where gross sliding occurs. The resolutio n of the microslip detection is 1 nm. Apparatus design and operation a re described, and the application and limitation of the method to a we akly nonlinear response are discussed and illustrated by experimental results with a polymer glass. (C) 1998 American Institute of Physics. [S0034-6748(98)00406-7].