Modeling And Simulation Research For Disc Brake Thermal And Thermoelastic Analysis

Brake is the key components of the vehicle brake system. It will be heatedduring braking by the frictional heat converted from the kinetic energy of the vehicle.The warming of brake will load to decrease of the friction coefficient and thermalstress which can affect the braking performance. The coupled temperature and stressfield analysis and calculation is an important method for the performance predictionand optimal design of brake.A ventilated disc brake was chosen to establish finite element models for thermalanalysis, including a simplified three dimensional model with just a rib and a wholethree dimensional model. Another simplified model and whole model wereestablished based on finite difference equations for comparison. The simplifiedmodel’s thermal load was uniform heat source and the whole model’s was movingheat source enforced by user subroutines DFLUX in ABAQUS. All models wereapplied in emergency braking and15-cycle braking. The simulation results showedthat the whole model result is more close to the true temperature field. Thetemperature of disc settled into a dynamic equilibrium after several cycle braking.The finite difference method (FDM) has the same accuracy of the FEM and higherefficiency. Based on FDM, software with man-machine interface for temperature fieldcalculation was programmed.Using direct coupling algorithm in ABAQUS, A three dimensional transientthermal and stress coupled FEM model including disc and pad was established. Themodel was applied in emergency braking and15-cycle braking. In order to reducecomputing time, the model just simulated the15thbraking by loading the thermalfield of the14thbraking obtained from thermal analyzing model as predefined field.Based on the results of the simulation of the thermal-mechanical coupling, thedistribution of the transient temperature, contact pressure and stress field of the discwere analyzed. The stress field had a certain influence on temperature. The thermalstresses were much greater than the mechanical stresses. The temperature field has adominant effect on the stress field. The two fields are highly coupled. With the alternating cycle of stress, the radial cracks on the disc surface were studied.