A Thermo-Mechanical Stress Based Fatigue Life Evaluation of a Mine Hoist Drum Brake System Using COMSOL Multiphysics

Abstract

In this study, the fatigue usage factors for Findley and Matake stress-based criteria were determined in the case of an MK5×2 mine hoist drum brake system subjected to cyclic maneuver braking. The study was conducted for this type of brake system, because the majority of mine hoists in Romanian mines are equipped with this brake type, being in operation for several decades. A geometric model of the brake was built using SolidWorks and imported in COMSOL Multiphysics to perform thermo-mechanical simulations. Based on the deformations and von Mises stresses determined by the thermomechanical simulation and, considering the calculated endurance limits of the brake system materials, Matake and Findley fatigue life evaluation simulations from COMSOL’s fatigue module were conducted. The results show that the highest fatigue is expected on the drum lining surface towards the exit point from under the brake shoe in both cases, and the values of the usage factor of 0.307 (Findley) and 0.401 (Matake) are both under the critical value 1, meaning that the stress limit has not been exceeded for the brake system components and, thus, failure is not expected. Simulations were conducted considering an estimated 1.06 × 105 cycles during one year, more than both the usual service/replacement interval of the friction components of the brake, and the period of mandatory technical inspections imposed by regulations.