The Simulation Analysis And Optimization And Design Process Of Power-train Mounting System

Automobile NVH is Noise (noise), Vibration (vibration) and Harshness (harshness orirregularity), and becomes the research focus in the field of automobile development andoptimization since it was put forward in1980s. It is a comprehensive index of measuring thevehicle quality. Engine assembly is one of the main automobile vibration and noise sources.Proper design of the power-train mounting system can improve the riding comfort anddecreasing the interior noise. The power-train layout space becomes small because of vehiclerefinement and energy-saving design; the new engine technology and new materials arebeing used in the automobile. Therefore, the mount system design is becoming more andmore difficult and the challenge enhance. So the power-train mount system is also designedand researched more and more deeply by all vehicle factories and the research methods arealso various, development tools is increasing and perfect. On the other hand, the research ofthe mount parts is becoming more mature and for OEMs these work are always completedby the supplier. However, the system-level development in our country is not yet mature,especially NVH calibration and matching is still in the stage of development. Based on this,the matching of the power-train mount system has been a subject concerned by the OEMs.The purpose of this study is to design and match a mount system of a SUV vehicle. Thepower-train of this vehicle is2.4L gasoline engine and5-speed manual gearbox. The specificwork is as follows:Firstly, the main drive on power-train mount system was combed and induced; thedynamic equation of power-train mounting system was derived by applying LagrangeEquation; the general equation to solute inherent frequency and formation of the power-trainmounting system was got; based on the engine vibration of single freedom degree, theproblem of engine vibration isolation was discussed, providing a theoretical basis forimproving the performance of the mounting system’s vibration isolation.Secondly, by reading the literature at home and abroad extensively, it focuses onstudying several basic issues in the power-train mount system design: measuring thepower-train parameter; typical mount layout and measuring the mount parameter. On thisfoundation, by summarizing the domestic and foreign advanced experience, the designprocess of the power-train mount system was elaborated systematically, providing importantbasis for the design of mounting system. Once again, according to the test, the vehicle power-train parameters and referencemount parameters were test. A simulation model is also built up by using MATLAB andADAMS separately with the model parameters obtained by experiments. Then he got themodal frequency and the energy distribution of all six order modals. He evaluated thepower-train mount system’s dynamic performance through its modal frequencies distributionand the vibration decoupling level.Last, combining with practical engineering, three spindle stiffness of the mount elementas optimize parameter, the objective function and constraint condition of mount systemdesign was build in MATLAB, decouple and optimize the mount system by using the energymethod, to realizes the reasonable configuration of power-train mounting system naturalfrequency and the system decoupling in the direction of main vibration, to design the mountsystem to reach the target value.In this paper, the method of combining theory with experiment was used during thedesign of mounting system. The dynamic equation of power-train mounting system wasderived by applying Lagrange Equation; the general equation to solute inherent frequencyand of formation of the engine mounting system was got; according to the test, the vehiclepower-train parameters and other model parameters were test, a simulation model is built upby using MATLAB and ADAMS separately, Then he got the modal frequency and theenergy distribution of all six order modals. Three spindle stiffness of the mount element asoptimize parameter, the objective function and constraint condition of mount system designin MATLAB was build, to realize the reasonable configuration of power-train mountingsystem natural frequency and the system decoupling in the direction of main vibration.The related study and work of this paper proves that the vibration isolation characteristicis improved by optimization and vehicle vibration and structural noise is obviouslyoptimization. Customer satisfaction gets better promotion. So the methodology used in thispaper has guiding significance for the mount system matching、design and optimization andis equally applicable to other mounting systems.