Friction Characteristics And Thermal Mechanical Coupling Analysis Of Disc Brake

Belt conveyor with smooth operation,continuity and strong anti-interference characteristics,is the ideal container and bulk materials transport equipment.At present,the belt conveyor has been moving towards long distance,high speed and heavy load.In order to meet the safe transportation of coal,this has put forward higher requirements for its braking performance.Disc brake has the advantages of good heat dissipation,high stability,large braking torque and compact structure,which could meet the requirements of belt conveyor.In the braking process,thermal recession,thermal cracking and material wear and other issues often occur,which seriously restrict the working performance of disc brake.Therefore,it is necessary to analyze the friction characteristics and thermodynamic coupling of the friction contact surface.Based on the theory of thermal analysis,this paper establishes a finite element model.By friction and wear tests,choosing different braking pressure and braking speed,the friction and wear of resin-based friction plate and copper-based friction plate are tested under dry friction and water lubrication conditions.Combined with the worn surface morphology analysis,the friction stability and wear resistance of copper-based friction plate are better.The temperature,thermal deformation and thermal stress curves of the disc surface are calculated by ABAQUS,and the three-dimensional transient thermodynamic coupling analysis is carried out from the axial,radial and circumferential.With the increase of braking pressure and braking speed,the thermal deformation increases gradually.The temperature characteristic curve and the stress characteristic curve are nearly linearly rising.While the braking pressure is 35 MPa,the corresponding temperature is 4.8 times the ambient temperature and the thermal stress is 5.6 times the braking pressure.The thermal deformation is caused by the frictional heat.When the temperature rising is low,the thermal deformation is not obvious.In 2s-4s,the thermal deformation increases approximately linearly.By analyzing the cloud of stress field and temperature field,it is seen that the temperature and stress at the contact are relatively large and reduce to the non-contact area at both sides.According to the dynamic characteristics of maximum temperature and maximum stress,it is found that the temperature and thermal stress are basically the same,indicating that the temperature field and the stress field are coupled with each other.By the different operating conditions of the system test,it is found that for the disc rotation of 3r/s,the system pressure from 6MPa to reduce,the required braking time is about 16 s.Comparison of test temperature and simulation with inlet and outlet of contact surface,it is seen that the temperature difference between the two is within 5%,indicating that the simplified model of discbrakes is feasible in theory.