Study Of The Numerical Simulation Of Truck Radial Tire's Vibration Noise

The NVH(Noise Vibration & Harshness) character of tire is one of the important factors that can affect the vehicle's NVH performance. It's a necessary demand in developing and producing tires to improve the NVH character of the tire and to reduce the noise of the tire. The developed countries, especially the Europe Unions, have legistated strict laws to forbid tires which noise level doesn't match the demand being sold in the market. It's very important and instructive in theory and engineering aspect to study the theory of tire noise and to develop the simulation and test method for tire noise, it can help developing and producing tires with lower noise.In this paper, under the base of analyzing the previous works, the simulation method is established that can be used to calculate the tire rolling noise and tire vibration mode and damping ratio. In order to realize the noise simulation of a rolling tire, the basic theory of how to decompose the kinematics of a rolling tire with large deformation and large rolling status was provided, the central difference calculation method was discussed too, which are the theoretic basises of the rolling tire simulation.The Helmholtz equations of the acoustics were discussed, the finite element method to solve the coupling of tire vibration and noise was deduced.The mechanical performance test of cured and uncured rubber was done, the parameters of the material model were obtained according to the test result, it's the basis of NVH simulation of the tire.The 3D ring model and finite element model was established to analyze the tire vibration phenomenon.The component analysis method was used to calculate the damping natural frequency and damping ratio. The influence of element type on the frequency calculating was studied. The smooth tire model and patterned tire model was calculated respectively and their influence on the frequency calculating was analyzed too. The demand on the tire model was made clear in calculating the tire natural frequency and damping ratio.The test method for the near field noise and far field noise was designed, the test of near field noise and far field noise of different tires with different patterns were done at different velocities.The mechanisms of tire noise and their characters of frequency were analyzed by the method of classifying different frequency.The method which can be used to assemble the pattern model and the smooth tire model to one integrated tire model was provided and implemented, the process of simulating the tire running state was defined, the acceleration field of the node of the outsurface of the tire pattern can be obtained.The Mixed Lagrangian-Eulerian method was developed which can be used in simulating the tire rolling vibration noise. The software of MLE method was programmed, using this software, the accelerations of the nodes on Lagrangian mesh can be translated to the accelerations of the nodes on Eulerian mesh. So the acceleration of the nodes on Eulerian mesh can be used to simulate the rolling vibration noise.In this paper, a new method was developed to simulate the tire rolling vibration noise, because it is based on the finite element method, so the material performance, the tire structure, the pattern and the working conditions of the tire can be taken into account. This method realizes tire noise simulation in time-domain, the comparison between the simulation and test result shows that this method is effective and reliable.