Research Of Broad Band Dynamic Absorbers Based On Finite Element Analysis

The bandwidth of dynamic vibration absorbers is a very important target in their working performance. Based on the mechanics principle, this paper makes use of finite element method to research the relationship between the degrees of dynamic vibration absorbers and their bandwidth, at the same time research their effect in the radiation-noise-field and designs their actual structures according to the models of analog computation.In the paper, the actuality and the trend of the research of dynamic vibration absorbers in all over the world are described, new idea and method are put forward according to the actual limitation. The finite element software (Patran/Nastran and Sysnoise) are introduced, the mechanics principle and the design parameters of dynamic vibration absorbers are also described in the paper.The paper research the vibration and noise control effect of dynamic vibration absorbers including single-degree of freedom and many kinds of multi-degree of freedom. First making use of finite element analysis software Patran/Nastran to analyze the frequency response, the paper add the dynamic vibration absorbers to the host system, impose a steady-state simper harmonic motivation on the host system, and then calculate the vibration displacement and the vibration velocity of forced vibration of the finite element nodes. The systematic models and the calculated vibration velocity are import into the acoustics analysis software Sysnoise to analyze the radiation-noise-field, calculate sound pressure and sound pressure level of the field points in the radiation-noise-field and study the impact of the dynamic vibration absorbers on the radiation noise of the host system. Finally, the paper designs actual structures of dynamic vibration absorbers according to the models of analog computation.The paper makes use of cantilever beam and fixed flat plat as the typical representation of multi-degree of freedom host system to analyze the relationship between the degrees of dynamic vibration absorbers and their effect. The technique ofthe research and the conclusions are valuable to other scholars' research in this field, further more, the dynamic vibration absorbers designed are valuable in practical application.