Thermal-Structure Coupling Analysis For Disc Brake Of Large Mining Belt Conveyor

With the development of belt conveyors and coal-mine production technology, the belt conveyor of long distance, large capacity, high power and high speed is more and more used in coal mine production. The braking performance of belt conveyor directly affects the braking safety and reliability. Braking failure of brake disc is mainly caused by thermal fatigue damage. Therefore the research on temperature field and stress field of conveyor brake disc in the braking process is of great significance to brake designing, optimizing and thermal fatigue studying. This thesis regards the brake disc of Shanyin Jinlong Coal line201belt of China Coal Group Shanxi G-ocean Energy Co.,Ltd as the research object, analyzing the thermal-structure coupling using finite element analysis software ANSYS. This thesis focuses as follows:(1) Describes the current situation of research on temperature field and stress field of brake and the basic theory of thermal-structure coupling. It mainly includes the way of heat transfer, the establishment of heat transfer differential equations and conditions determining solutions and finite element theory of thermal-structure coupling analysis. The finite element model is established according to the actual size of the brake disc. The material relevant parameters are determined. The thermal load and boundary conditions are confirmed.(2) According to the actual working condition of conveyor system determine the braking parameters under three braking conditions, which are normal braking condition, the entire system with coal suddenly without electricity condition and only in the downward section with coal suddenly without electricity condition. The transient temperature fields under three different braking conditions are simulated and the results are analyzed in detail and compared. The results show that the temperature of disc friction surface under three different conditions is of the same tendency, increased first and then decreased. The entire system with coal suddenly without electricity condition has the highest temperature raise. The temperature field of the test-bed brake disc is simulated and the infrared temperature measurement is carried out on the brake disc. By compared with the simulation results and the measurement results, the credibility of the temperature field simulation analysis methods is indirectly verified. The influence of different thermal physical parameters on the temperature field is analyzed. Designed two different structures of brake disc: reinforced plate structure and pore structure. Their temperature field are investigated. The results show that the reinforced plate structure is more advantageous to the ventilation and heat dissipation. However, at design time, bearing in mind that the structure of ventilation and steel size effects on the temperature field.(3) The stress analysis of brake disc is done with sequentially thermal-structural coupling analysis under the normal braking condition. The stresses fields under three braking condition are compared. The results show that the stress variation trends of each node of disc are basically identical with temperature variation trends. Disc fraction surface area stress is the largest. Under normal working condition, the braking is safe. However, under the other two conditions the systems suddenly without electricity are dangerous situations for the maximum stress exceeds the disc material yield limit, which may make the brake disc produces thermal damage and cause brake failure.