Study On Pure Electric Vehicle Powertrain Mounting System Of NVH Performance Optimization

In this paper,a pure electric vehicle model is involved.Aiming at the problem of excessive vibration and squealing of its powertrain in the early stage of development,through the analysis of its experimental modal characteristics,It is considered that the excessive vibration of powertrain is caused by the unreasonable distribution of natural frequency and decoupling rate and the problem of modal coupling in the mount system,which will not only affect the NVH performance of the mount system.It will also affect the service life of the powertrain,so the natural frequency and decoupling rate of the powertrain mount system need to be re-matched,and the vibration isolation rate needs to be optimized.Through filtering analysis of the test noise curve,it is concluded that the excessive noise is caused by the high pressure level of the high frequency noise.1.The problem of the high frequency noise of the powertrain needs to be solved.In order to improve the NVH performance of the powertrain mount system,this paper mainly studies the following aspects.2.The experimental modal characteristics of the powertrain mount system are obtained through the test.It provides the data support and guarantee for the optimal analysis of the vibration characteristics of the mount system.the virtual prototype model of the mount system is established in ADAMS with the relevant test modal parameters of the mount system provided by the manufacturer,and the modal characteristics of the mount system are calculated.On the one hand,this work can verify the accuracy of the mount-related test modal parameters provided by the manufacturer,on the other hand,it can calculate the first six-order mode decoupling rate of the mount system in ADAMS,and on the other hand,It is also possible to calculate the response dynamic reactions of three mount points under the condition of high torque sine periodic excitation in ADAMS.It provides data support and guarantee for the optimization of the vibration characteristics of the mount system.3.The dynamic equation of the mount system is established by Lagrange dynamic equation,and the relevant modal parameters of the mount system are replaced.The optimization model is established in MATLAB,and the calculation of the optimization program is completed.The vibration characteristics of the powertrain mounting system are optimized.On the other hand,the virtual prototype model of the mount system in ADAMS is updated with the optimized modal parameters of the mount system,and the response dynamic forces of the three mount points under the same large torque sine periodic excitation are calculated and compared with the previous ones.4.Aiming at the problem that the high-frequency screeching of the total power cost volume has too much influence on the vehicle in the early stage of development,the design improves the influence of the high-frequency screeching of the total power cost volume on the vehicle on the basis of the analysis method of the transmission road force.