Accelerated Thermal Ageing Effects on the Braking Performance of Hoist Brake Discs

The disc brake is an essential part to achieve safe operation and stable braking in the hoisting mechanism of cranes. However, degradation of braking performance is inevitable in engineering practice due to repeated heavy loads, significant temperature variations and high dust concentrations. To investigate the characteristics of the brake-friction pair under working conditions, accelerated tests and a series of simulation analyses were conducted in this paper. Dynamic braking torque, wear volume, and friction coefficient under different working conditions were obtained and analysed based on a brake test rig and a thermo-mechanical coupling simulation model. The experimental results show that the initial braking torque drops from 1273 to 900 N·m as the ambient temperature increases from 0°C to 55°C. Based on polynomial regression of the measured disc thickness loss, the predicted service life of the brake disk is 8900 cycles at 0°C, 5220 cycles at 15°C, and 4790 cycles at 55°C. Simulation results further reveal that each braking event induces irreversible plastic deformation and residual stress in the disc, with a maximum equivalent stress of 80.6 MPa and a peak temperature of 56.3°C under the tested conditions. These findings provide a quantitative basis for the design, selection, and maintenance of hoist brake discs in different thermal environments.