Thermal-Mechanical Coupling Analysis And Optimization Of The Hydraulic Disc Brake For Drilling Rig

As a key component of the winch, the hydraulic disc brake for drilling rig directly affects the rig performance. The surfaces of friction pairs would produce a large amount of heat that results the disc surface tends to produce thermal fatigue cracks, which may make the brakes failed during braking. So the hydraulic disc brake for drilling rig has the security risk. Therefore, thermal-mechanical coupling analysis and optimization of the hydraulic disc brake for drilling rig was researched, which has a very important significance in safeguarding the safety of drilling equipment and workers.Based on the hydraulic disc brake for drilling rig as an example, the thermal-mechanical coupling analysis and optimization of the hydraulic disc brake for drilling rig was researched. The main contents and conclusions are as follows:(1)According to the actual geometry size, a three-dimensional model of the water-cooling hydraulic disc brake for drilling rig could be established by using the pre-processing module of finite element software ABAQUS. The software Hypermesh was applied to mesh the friction pairs. Based on the theory of thermal-mechanical coupling, the corresponding boundary conditions were setted up. The simulation model of the water-cooling hydraulic disc brake for drilling rig was established by the software ABAQUS.(2) According to the different characteristics of braking conditions, the coupling simulation of three-dimensional transient temperature field, stress field of hydraulic disc brake for drilling rig was studied. And the distribution characteristics and variation disciplinarian of temperature field, stress field of the brake disc were obtained in emergency braking condition, parking condition, repeated braking condition. The research showed that the distribution of temperature field, equivalent stress field of the brake disc firstly appears non axisymmetric distribution. The maximum temperature and maximum equivalent stress is serrated upward tendency. With the increase of the braking time, the distribution of temperature field, equivalent stress field of the brake disc would gradually tend to be axisymmetric. The temperature value and equivalent stress value on the entire surface of the brake discs is higher. The maximum temperature and maximum equivalent stress is serrated downward tendency. During braking, the radial and axial temperature gradient of brake discs surface are larger, the circumferential temperature gradient of brake discs surface is smaller. The circumferential stress is larger than the radial and axial stress, and the axial stress is smaller.(3)The parameters of working conditions and material characteristics, which affects the distribution of temperature field, equivalent stress field of the brake disc, were studied by using the controlling variable method. The research showed that, for the brake discs, reduction in its maximum temperature and maximum stress could be achieved by reducing the braking initial velocity, braking pressure, increasing the cooling water flow velocity, heat convection coefficient and other parameters of working conditions, reducing the friction coefficient, elastic modulus, thermal expansion coefficient, increasing thermal conductivity, the specific heat capacity and other parameters of material characteristics.(4)The optimization methods of the parameters of working conditions and material characteristics were established in order to optimize the heat dissipation properties for the brake discs. The research showed that, the maximum temperature value drop by 12.409%, the maximum equivalent stress value drop by 13.379%. It proved that the overall optimization methods are true.The conclusions of simulation analysis provide a theoretical guidance for optimization design of the hydraulic disc brake for drilling rig.