Application Of Dynamic Vibration Absorber In Automotive NVH Performance Optimization

When the excitation frequency is consistent with the system natural frequency,resonance will occur.Resonance is one of the leading causes of automobile vibration and noise. Vibration absorber can effectively attenuate the vibration in a certain frequency range, and it is simple and practical,need not to change the structure of the vehicle itself.When the excitation frequency has already been known,the reasonable design can effectively improve the effect of vibration absorber.It has proved to be one of the important means in the vehicle NVH design and debugging.In this paper, a dynamic vibration absorber is designed for the engineering practice on the basis of the research and the LMS test equipment,concretely introduces the technology and research and development of the dynamic vibration absorber which is used to the background, with specific examples of the detailed description of vibration absorber which is used to create and use.The vibration-absorbing effect change can be realized through punching holes in the natural rubber of the dynamic vibration absorber.In this paper, combined with the finite element simulation and experimental test,it analyzes the influence on auto parts vibration characteristics caused by parameters of absorber,and the variable density method is adopted for the optimization of the shape of the rubber.First of all, this paper analyzes the common problems in the development of NVH in the car, represented by problems caused by the transmission shaft, the front subframe, rear axle components,through comparison with the front and rear noise sound pressure values, as well as vibration amplitude of several representative points on parts, it analyses the influence of quality, location, number of dynamic vibration absorbers from the perspective of test.Then, by using the finite element software to establish a car rear axle element model, analyses the vibration absorption effect through the frequency response simulation of different groups.The influence of factors on its effect will be known comparing results.Finally, this paper optimizes the dynamic vibration absorber in order to achieve the best effect of vibration reduction,natural rubber for vibration absorber which is used to punch on the location and size of the object to optimize the design, the vibration of a few points on the rear axle as the optimization goal, through the topology optimization method, the natural rubber is divided into hexahedron units, and through the finite element software and application of variable density method for vibration absorber design and optimization, determines the location and shape of vibration absorber.By optimization of practical engineering vibration absorbing,and through three reference points to analyze the vibration amplitude optimization effect.Research contents and research methods of this article can provide theoretical guidance for the vehicle’s harshness(NVH) adjustment, can reduce the development costs and cycles of car, has a good engineering practice significance.