Optimum Design Of Powertrain Mounting System For A Vehicle

As the development of auto industry, automotive power performance andcontrollability and stability can meet the needs of peolpe’s daily life, and people pay moreclose attention to the riding comfort. Vehicle’s NVH(Noise Vibration and Harshness)issue becomes one of the most important indicator of a car brand. By optimum design ofthe powertrain mounting system, a vehicle’s vibration and noise can be restrained, and theNVH performance will be improved accordingly.Based on a large number of references and enterprise’s exploiting experience formany years, the powertrain mounting system of a car is designed. Firstly, the location ofthe mounting system is arranged based on the principle of torque roll axis, which makethe elastic axis parallels with the torque. Secendly, to insure the mode frequency of activeand passive parts are larger than500Hz, the suspension bracket is analysed by simulatesoftware and verify by testing. Thirdly, based on the energy decoupling theory, mount’sstiffness is optimal designed by the Isight and Matlab software, which makes the systemnatural frequency between5.5Hz and17Hz meanwhile the decoupling rate of Bounceand Pitch are larger than95%. Fourthly, A Multi-Body dynamics model is built andverifyed by ADAMS. By sensitivity analysis, It is found that the most influencing factorsto the decoupling rate of Bounce and Pitch are the stiffness of W direction of left and rightmount apart from the stiffness of U direction of torque strut. Then, A displacement controldesign is given in ADAMS, which make sure that powertrain mounting system’stranslation is less than±15mm and rotate angle is less than5degree. Finally, severalschemes are presented based on the optimized stiffness. By testing in the whole vehicle,the preferable plan of mounting stiffness is finded out. The whole exploitation process hasa high application value and is useful for other car models.