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 multicontact interface between flat-ended solid bodies, rough at the micron scale. The device makes use of inertia to apply a steady sinusoidal shear force to a slider without direct mechanical drive. Both elastic compliance and damping losses are deduced from the in-phase and out-of-phase components of the submicronic shear displacement. Operating frequencies range between 15 Hz and 1 kHz, while below 100 Hz quasistatic motion of the slider is achieved. Acceleration amplitudes range typically between 0.1 and 7 m $s−2,$ where gross sliding occurs. The resolution of the microslip detection is 1 nm. Apparatus design and operation are described, and the application and limitation of the method to a weakly nonlinear response are discussed and illustrated by experimental results with a polymer glass.