Structural Optimization And Fatigue Life Prediction Of Disc Brake For Deep Well Hoist Based On Thermal-mechanical Coupling

At present,deep mine mining is the mainstream direction of coal mine development.In order to improve efficiency,deep well lifting generally adopts large tonnage lifting,and at the same time,due to the complicated working conditions,the number of emergency braking will increase.Disc brakes are the core components of deep well hoists.The heat and thermal stress generated during braking can cause the brake service life to be reduced,posing a safety hazard.Therefore,deep well lifting has higher requirements for disc brakes,and it is more practical to study the thermomechanical coupling of deep well hoist disc brakes.In this thesis,taking a deep well hoist disc brake as an example,combining the existing research results with the actual working conditions,the following research is carried out:(1)According to the actual size of the brake,the finite element modeling of the disc brake is carried out by using ABAQUS finite element analysis software.Under the condition of ensuring the accuracy of analysis,the model is reasonably simplified and meshed,and the boundary conditions required for thermo-mechanical coupling are set according to empirical formulas and theoretical formulas.(2)Using the thermo-mechanical coupling solver in ABAQUS to solve the finite element model,analyze the distribution law of the brake shoe and the temperature field and stress field of the brake under emergency braking conditions,and distribute the brake shoe temperature.The cloud image is compared with the actual wear position of the brake shoe.The influence of braking speed,friction coefficient,brake pressure and the angle between adjacent brake shoes on the thermo-mechanical coupling of the brake is discussed by using the control variable method.(3)Taking the outer radius of the brake disc,the length and width of the brake shoe as the design variables,the design variables are sampled and taken through the experimental design in Isight software,and an approximate model of simplified optimization calculation is established based on the simulated data.Taking the maximum stress of the brake disc as the constraint condition and taking the maximum temperature of the brake disc as the optimization target,the structure of the brake is optimized by the combination algorithm of ASA algorithm and NLPQL algorithm.(4)Based on the results of thermo-mechanical coupling,determine the form and location of fatigue damage of the brake disc,analyze the cause of fatigue failure,and use the Masson-Coffin formula to predict the fatigue life of the brake disc.