磁橡胶约束阻尼悬臂板的阻尼特性

Damping Property of a Cantilever Plate with Magnetic Rubber Layer Damping Treatment

研究了磁橡胶约束阻尼处理(MRLD)悬臂板的阻尼特性。应用假设模态法,计算传统被动约束阻尼处理(PCLD)的频率响应,并基于周期耗能相等原理,将MRLD与PCLD等价,得到MRLD板模态损耗因子。采用MRLD处理,起滑力F0随着阻尼层厚度hv、约束层厚度hc的增加而增加;频率高的模态的F0高于频率低的。发生滑移后,随着简谐激励力F的增加,系统损耗因子η增加,达到极值后便下降。在给定F下,提高hv,η增加,但hv较厚时,η增加缓慢。对一特定的hc,可获得最大的模态损耗因子。对板的其他高阶模态的类似分析也可得到类似的结论。

In this paper, the damping property of a cantilever plate with magnetic rubber layer damping treatment （MRLD） was investigated. With the assumed-mode method, the frequency response of a cantilever plate with passive constrained layer damping treatment （PCLD） was calculated. The modal loss factor η of the MRLD plate was obtained based on the derived equation of the PCLD plate by equating the dissipation energy by MRLD to that by PCLD in a vibrating cycle. The results reveal that, using MRLD, the start slide excitation force F0 increases as the damping layer thickness hv or the constraining layer thickness hc increases. The higher the modal frequency is, the greater F0 is. After slip occurs, increasing excitation force F increases η to an ultimate value, while η decreases as F continues to rise. Under a given force F, although increasing hv increases η, the damping improvement is not significant for thicker damping layer. A maximal modal loss factor can be obtained at a particular constraining layer thickness he. The similar conclusions can also be drawn for different resonant modes.