Optimization Design Of Powertrain Mount And Study Of Hydraulic Mount Performance

Vibration and noise of powertrain generated in the course of their work is a majorcomponent of the vehicle’s vibration and noise is an important indicator of the car ride comfort.With the development of society, people’s living standards are continuing to improve, and themore stringent requirements of vehicle vibration and noise are put forward. So to effectivelycontrol vibration and noise of powertrain has become an important research topic.Firstly, in this paper the author introduces the role of the powertrain mounting system,structure, as well as domestic and foreign development status and analyses the law of motionand force of crank-connecting rod mechanism of four-stroke internal combustion engine, aswell as the impact of balance and vibration of the internal combustion engine and presents thelayout and design principles of Mounting system. In this paper, a six-degree-of-freedompowertrain mechanical model and coordinate system of powertrain mounting system wereestablished and mass matrix, stiffness matrix, the system natural frequencies and mode shapesof powertrain mounting system under the torque-axis coordinate system were derived. Inaddition, each Optimization objective function was introduced and the selection principle ofoptimization variable and constraints were analyzed in the optimization process. Meanwhile,energy decoupling and sequential quadratic programming (SQP) optimization algorithm wereadopted in the optimization process, and the optimal design of suspension system with thedifferent objective function was realized by using optimization tools fgoalattain function inMatlab toolbox to finish the rational allocation about natural frequency of mounting system andenergy decoupling,as well as optimization design of system vibration transmissibility and theminimum reaction force in the mount. In order to achieve a better man-machine interfaceexchange in the op timization process，the vibration characteristics optimizer of the suspensionsystem based the GUI modules in the MATLAB software was developed. And In order to runin the Windows environment out of the MATLAB, the software was packaged. According toparameters of powertrain inputted by user, not only can the software easily calculate the massmatrix and stiffness matrix of powertrain, but also it can count the natural frequency and modeshapes of the mounting system. According to different objective functions, the initial stiffnessand the installation location and other relevant parameters of powertrain mounting were easilyoptimized, and rational arrangement and matching of the powertrain mounting system wererealized. The software system which includes the parameter input interface, vibration analysisinterface and optimization interface can not only input parameters and calculate data but alsooutput and save data. The data can be saved automatically as a.txt file or. Mat file. Theoptimization system greatly facilitates the early development of the powertrain mounting system. In the last chapter, according to the typical hydraulic suspension structure, hydraulicsuspension mechanics and mathematical model were established, and the hydraulic suspensionwas simulated based on Matlab/Simulink. Finally, the influence law of the main structuralparameters of the hydraulic suspension on its performance was not only analyzed andsummarized but also validated in the test.