| The vibration between the vehicle powertrain and the frame is isolated by the mounting system,so the vibration isolation performance of the mounting system plays a vital role in improving the comfortableness of the vehicle.The noise reduction and vibration damping functions of the mounting system are realized by the rubber mount and the bracket.In order to improve the NVH performance of the vehicle,this paper analyzes the mechanical properties of the rubber mount and the bracket by using the finite element software,and optimizes the design of the vehicle powertrain mounting system,which provides a basis for the mount development.In this paper,the rubber mount of three different hardness compounds in engineering applications is studied,and the static characteristics of rubber mount are analyzed and discussed by finite element method and experimental method.A design and development method of bracket areproposed.This paper contents include as following:(1)The basic theories of different rubberconstitutive models are analyzed,and the different research methods of rubber constitutive model are discussed in detail.The applicability and characteristics of therubber constitutive models are compared and analyzed,and the fitting methods of material constants of rubber constitutive model are also discussed.(2)The stress deformation form,the equivalent method,the experimental principle and the problems needing attention in the experiment of the rubber material are analyzed.Three kinds of rubber materials with different hardness were tested on mechanical properties,and the test including uniaxial tension,plane shear and equiaxial stretching test.Under different hardness and different maximum strain conditions,the fitting accuracy of different constitutive model parameters are compared and analyzed.(3)The static characteristics of different types of rubber mounts are analyzed.The static stiffness simulation results of N50-8 are verified by experiments.And the static stiffness of the suspension of N45-8,N50-8 and N55-8 are compared and analyzed by taking the static characteristics of rear suspension of a vehicle as an example.The effects of material parameters and strain levels on the calculation results of static characteristics of rear suspension are analyzed.(4)The strength of a suspension bracket was analyzed by finite element method and failure experiment.Based on the experiences of design and development of a large number of suspension supports,a method for guiding new bracket is proposed.The validity of the new method is proved with some instances. |
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