Investigation on the friction and wear characteristics of longitudinal sliding of monorail crane drive wheels under thermo-mechanical coupling

As a key component of modern auxiliary transportation systems in underground mines, the monorail crane is essential for the safe and efficient “last-mile” transfer of materials. The driving wheel is the core element enabling stable traction and high-efficiency conveyance. Under heavy loads and in environments with steep gradients and curved tracks, longitudinal slip between the driving wheel and the rail can readily occur, accelerating wear and even causing fracture failure, thereby posing serious risks to transport safety. Heat generation at the wheel–rail interface further aggravates wear and compromises the operational safety of coal mines. Therefore, investigating the friction and wear characteristics of the driving wheel under thermo-mechanical coupling. Field tests were conducted to obtain the slip-ratio distribution, indicating that slip ratios of 0–10% occur with high probability. Based on this range, rolling contact wear tests were performed at various slip ratios to quantify wear, and the Archard wear model was modified to account for temperature effects. A thermo-mechanically coupled finite element model of the driving wheel under longitudinal slip was then developed in ABAQUS. By integrating simulation and experimental results, the distributions and evolutions of contact pressure, inner-wall stress, temperature field, and wear morphology during slip were systematically analyzed. Finally, underground engineering trials were carried out to validate the predicted wear patterns. The results show that slip ratio is a key factor governing interface temperature rise, wear acceleration, and fracture failure of the driving wheel. When the slip ratio increased from 0 to 9%, the maximum interfacial temperature rose from 28.58 ℃ to 64.15 ℃, and the wear volume increased by a factor of 10.17. Temperature changes markedly affected wear morphology: thermal softening redistributed contact pressure from the wheel shoulder toward the crown center, forming an arch-shaped pressure profile, and shifted the dominant wear mechanism from abrasive wear at low slip ratios to adhesive wear and material spalling at high slip ratios. Moreover, high slip ratios substantially increased the inner-wall stress near the wheel shoulder, which promoted fracture failure of the outer polyurethane layer. Agreement among simulations, laboratory tests, and engineering validation confirms that slip ratio is the critical contributor to surface temperature rise, aggravated wear, and ultimately fracture failure of the driving wheel. The friction and wear behavior of the driving wheel under longitudinal slip is investigated, the governing mechanisms of thermo-mechanical coupling are elucidated, and a theoretical basis for optimal wheel design and safe operation is provided.