INVESTIGATION OF SCHALLAMACH WAVE FORMATION AND PROPAGATION IN BELT-DRIVE SYSTEMS: TRIGGER MECHANISMS, CHARACTERISTICS, AND PREDICTIVE MODELING

A comprehensive investigation is conducted using a high-fidelity dynamic finite element model to explore the impact of Coulomb friction coefficient and adhesion stress on stick-slip events over the driver and driven pulleys in one-pulley belt-drive systems. The model shows that at Coulomb friction coefficient below a certain critical value, the belt undergoes pure sliding in the slip arc on driver and driven pulleys with no stick‐slip dynamic events. Above that friction coefficient value dynamic stick‐slip events start to occur in both driver and driven pulleys resulting in torque pulses, which for practical belt‐drives may cause non‐smooth operation, excessive belt noise and/or excessive belt wear. For driver pulleys the dynamic stick‐slip events are in the form of Schallamach waves, while for driven pulleys the dynamic stick‐slip events are in the form of expansion pulses. The model results are validated against experimental results.

Furthermore, a sensitivity study was conducted to examine how operational, material, and geometric parameters influence the formation and propagation of Schallamach waves in belt-drives. Response parameters such as total belt strain energy density (U), inception angle (θ), propagation angle (Δθ), and time between pulses () are used to quantify the waves' effects. Statistical analysis via analysis of variance (ANOVA) reveals varied responses and effects of the studied parameters on the belt and Schallamach wave propagation over a 2-second timeframe with a resolution of 0.001 seconds per parameter change.

Finally, wave speed analyses were performed to characterize the development of Schallamach waves based on established academic and research literatures. These results were compared against the sensitivity analysis findings, providing deeper insight into the ranking and influence of the operational, contact, material, and geometric parameters on the onset of Schallamach waves within belt-drive systems.