Dynamic Simulation And Thermal Analysis Based On Rigid Coupling Model Of Drum Brake

Drum brake is the device that converts kinetic energy of vehicle traveling to heat and then emits to the atmosphere, to make the car slow down or stop. Drum brakes are widely used on the rear wheel of small cars and most economic vehicles. The analyze of its torque and thermal performance during the work process is of great significance. Due to the consideration of economy and time, test cannot be easy. We can make qualitative analysis by method of system simulation. In this paper, based on the multi-rigid and flexible multi-body and thernoelasticity, making the dynamic and thermal structural analysis of drum brakes. The main content is as follows:1)First, make theoretical torque calculation drum brakes, calculating the required cam torque,vehicle equivalent moment of inertia and the initial velocity of the drum in the time of braking of the vehicle. Establish various parts of the drum brake with CATIA and assemblaging the parts to get the assembly model, providing the model basis for the following power and thermal analysis.2)Using the interface of three-dimensional geometric modeling software CATIA and multi-body dynamics simulation software ADAMS, generating multi-body dynamics solid model of drum brakes in the simulation environment. And modal neutral file will be generated by using the finite element software Hypermesh and imported to multi-body dynamics software to further generate rigid-flexible coupling model and to determine the appropriate boundary conditions, establish the various constraint, sports vice friction and resistence of the spring, get dynamic analysis of the system in two different coefficient of friction, output load on the cam, the acceleration curve of the brake drum and Fourier transformation curve, the pressure curve of nodes in the friction linings, and analyze the output results.3)In order to further consider the actual situation of the brake drum and analyze the reasons for the failure of heat, based on the consideration of structural stress field and temperature field, establish the thermal structure finite model of the drum brake considering the above simulation analysis with the prokinetic boundary conditions. And imported into ABAQUS to make thermal structure coupling analysis of drum brake, getting drum brake temperature stress distribution law in the mutual coupling effect. Finally,based on the simulation model, investigated the influence of the material, the friction coefficient and the different loads on the brake drum temperature rise.The results show that:In large coefficient of friction, braking acceleration is significantly increased, and braking performance improves, but on the view of the acceleration Fourier transform curve, the poingt caused resonance increased, brake will cause automotive resonance, and the excessive friction will accelerate brake drum temperature rise. Therefore, the choice of coefficient of friction should weigh the various demands, to improve the thermal conductivity of the drum material is more effective than the heat capacity to reduce the temperature rise of the drum. Have a high specific heat capacity and thermal conductivity of the materials selected should as far as possible in the actual selection.