Research On Vibration And Noise Characteristics Of Dual Clutch Transmission For Hybrid Electric Passenger Vehicles

In recent years,with the deterioration of the ecological environment,the country has put forward more stringent requirements for the emission index of cars,and hybrid cars have become a hot spot for research and development of major car companies,while the dual-clutch transmission（DCT）itself has the characteristics of fuel saving and energy saving,so it is chosen by many new energy vehicles.This paper was completed under the joint support of the National Natural Science Foundation of China（NO.51775222）and the Science and Technology Development Project of Jilin Province（NO.20200401136GX）.The paper elaborates the current situation of domestic and foreign research and application prospects of DCT in the field of new energy vehicles.The "Automatic Modeling Design Platform for DCT Transmission Gear Set" was built based on VB language for the modeling process of DCT,which greatly improves the modeling efficiency.The vibration characteristics of the DCT was investigated by the finite element analysis method,and the noise characteristics of the DCT was investigated by the boundary element method.The results of this paper are useful for the automatic modeling aspects of DCT and for improving the vibration noise.Automatic modeling design software related to DCT was written based on VB language in combination with CATIA.The influence of machining and assembly errors on modeling was analyzed in detail in the writing of the software,and both were innovatively and fully considered in the compilation of the automatic modeling software.Based on the written software combined with the parameters of the DCT given by the company,a three-dimensional model of the DCT with random error properties was successfully built.A dynamics simulation analysis of a DCT based on RecurDyn was carried out.A continuous upshift condition and an actual limit condition in reverse gear were simulated to check the input shaft speed,output shaft speed and the instantaneous transmission ratio of each gear.The data processing and comparison proved that the dynamics of this DCT can meet the conditions proposed by the company very well.The contact forces between all meshing gear pairs were extracted in the reverse gear condition,providing realistic excitation parameters for subsequent vibration characterization.Based on ANSYS（Workbench）,the vibration characteristics of the reverse gear of the DCT were analyzed.Firstly,the static simulation analysis of the DCT was carried out to verify that the stiffness and strength of the DCT meet the standard requirements.Then the modal analysis with pre-stress was carried out to obtain the first six orders of modal vibration patterns and intrinsic frequencies of the DCT,which provides a basis for evaluating the vibration characteristics of the DCT.Finally,the frequency response analysis was carried out with the real excitation extracted from the dynamics analysis to analyze the dangerous frequencies of the DCT under real operating conditions and their hazards.The noise characteristics of the reverse gear of the DCT were analyzed based on the acoustic software LMS Virtual.Lab.By looking at the frequency-sound pressure function graph,it is concluded that the frequency corresponding to its extreme value point is approximately the same as the hazard frequency corresponding to the vibration frequency response graph,which proves the accuracy of the acoustic simulation.The frequency-pressure function graph was then analyzed in detail and the frequency corresponding to the maximum noise was determined,and the sound pressure distribution clouds at this frequency were retrieved and finally compared with the national industry standard for automotive transmission noise,proving that the noise value of this DCT meets the industry requirements.In summary,automated modeling,dynamics analysis,pre-stress modal analysis,frequency response analysis and acoustic simulation analysis were conducted to study the vibration and noise characteristics of the DCT.The research results of this paper lay a certain foundation for the subsequent in-depth study of DCT modeling and NVH,and provide a certain reference value for domestic independent brand vehicle enterprises to improve the NVH performance of their vehicles.