Friction-induced interactions: acoustic emissions, vibrations, and wear – a multiscale review
Paweł Olejnik, Yared D. Desta
Abstract
Friction-induced phenomena such as acoustic wave emission, vibration, and wear remain critical challenges in tribology due to their nonlinear, interdependent nature. The relative motion between contacting bodies generates both internal oscillations and radiated sound, yet these effects are often studied in isolation, limiting a full understanding of system dynamics. This review bridges the gap by integrating current knowledge of acoustic friction, friction-induced vibration, wear mechanisms, and wave propagation in solids. Emphasis is placed on surface characteristics, lubrication, and material properties as key contributors to dynamic instabilities like stick-slip, mode coupling, and sprag-slip. Analytical models and case studies highlight the acoustic and vibrational responses of various material systems, including polymers, composites, and bolted joints. The experimental section illustrates the coupling between stick-slip motion and acoustic emission using a 2-DOF beam-table setup. Measurements synchronized in time and FEM simulations reveal transient wave bursts and spatial distributions of sound pressure levels during dynamic contact. Together, this review provides a unified perspective on friction-induced acoustic behavior and demonstrates its relevance for mechanical diagnostics, design optimization, and energy-aware applications.