Design and characterization of an instrumented slider aimed atmeasuring local micro-impact forces between dry rough solids

TL;DR

This paper presents an innovative instrumented slider with piezoelectric sensors designed to measure micro-impact forces at the asperity level during dry rough sliding, enabling detailed analysis of micro-impacts and related phenomena.

Contribution

The study introduces a novel sensor array embedded in a slider to directly measure micro-impact forces and positions, validated through experiments and modeling.

Findings

Sensor array accurately measures impact forces and positions.

Dynamical characteristics match finite element model predictions.

Validated with tracks of known topography.

Abstract

Sliding motion between two rough solids under light normal loading involves myriad micro-impacts between antagonist micro-asperities. Those micro-impacts are at the origin of many emerging macroscopic phenomena, including the friction force, the slider's vibrations and the noise radiated in the surroundings. However, the individual properties of the micro-impacts (e.g. maximum force, position along the interface, duration) are essentially elusive to measurement. Here, we introduce an instrumented slider aimed at measuring the position and the normal component of the micro-impact forces during sliding against a rough track. It is based on an array of piezoelectric sensors, each placed under a single model asperity. Its dynamical characteristics are established experimentally and compared to a finite elements model. We then validate its measurement capabilities by using it against a track bearing simple, well-defined topographical features. The measurements are interpreted thanks to a simple multi-asperity contact model. Our slider is expected to be useful in future studies to provide local insights into a variety of tribological questions involving dry rough sliding interfaces.