Research On Vibration And Noise Control Strategy Of Special Vehicle With Integrated Powertrain Unit

Special vehicle is an important road transport vehicle due to its superior antipreparation performance and strong transportation capacity.In recent years,the vibration and noise performance requirements of special vehicles are growing higher and higher.Among them,the vibration noise of the cab has become one of the research hot topics because of its important influence on the driver.However,since the special vehicle adopts the powertrain integrated unit structure and the vehicle body is welded by a large member of metal plate,the vibration of the powertrain propagates to the vehicle body through the structure of the special vehicle,causing structural radiation noise of the body panel surface;The noise of the vibration source propagates through the holes and slits between the structures,resulting in bad vibration and noise environment of the special vehicle cab.Therefore,it is of great theoretical and engineering value to carry out the research on the vibration transmission characteristics of special vehicles and the control technology of vibration and noise in the integrated unit of powertrain.In this paper,aiming at the problem of the large vibration and noise of the special vehicle cab with powertrain integrated unit,the research on vibration characteristics analysis,vibration control strategy and noise control strategy is carried out.The main research contents of this paper are as follows:(1)The vibration analysis model of special vehicle was established,and the vibration characteristics of special vehicle cab was analyzed based on transfer function.The transfer function of 42 paths of 7 excitation points and 6 response points was studied,and the critical path and mode affecting the vibration characteristics of the cab were analyzed which laid the foundation for the vibration and noise reduction design of the special vehicle cab.(2)The vibration control strategy based on the modal contribution of the special vehicle is proposed.Through the optimization design of the three factors which are body structure: powertrain support structure,and powertrain damping pad,the vibration of special vehicle is controlled.The influence regular of matching design between powertrain support structure and body structure is analyzed.(3)The noise control strategy for metal plate local resonance and irregular holes and joints is proposed.On one hand,the noise reduction design is carried out based on acoustic transfer vector for metal plates that generate local resonance;on the other hand,the universal design is carried out for irregular holes and joints,which replaces the customized design of sealing elements and realizes the control of the whole vehicle research and development cost.The acoustic simulation model is established and the effectiveness of noise reduction design is verified by the acoustic simulation analysis.(4)The vibration and noise test for the special vehicle is carried out,and the vibration and noise data of the special vehicle before and after the optimization under 7 uniform conditions is obtained.The vibration and noise control strategy proposed in the chapter 3,4 and the effectiveness of special vehicle vibration and noise reduction design is verified.