采用集中质量法计算了一维花岗岩/丁腈橡胶声子晶体的振动带隙,研究了集中质量数、晶格常数、组分比及丁腈橡胶的粘弹性对带隙的影响.结果表明,增加集中质量数能提高带隙精度,晶格常数及组分比对带隙结构有较大影响,而丁腈橡胶的粘弹性能增大带隙宽度.根据以上结论,对声子晶体的材料参数和结构参数进行了优化,设计出1种能屏蔽人耳最敏感的1.5~2.5kHz噪声的一维声子晶体.
The lumped-maRs method was employed to calculate the vibration band gaps of one-dimensional phononic crystals consisted of granite and nitrile rubber, the effects of the number of lumped-mass, lattice constant, volume fraction and viscoelasticity of nitrile rubber on band gaps were also investigated. It could be concluded that the accuracy of band gaps can be improved by increasing the number of lumped-mass, the band gaps are remarkably affected by the lattice constant and volume fraction, in addition, the viscoelasticity makes the width of band gaps increase. Finally, material and structure parameters of phononic crystals were optimized base on our results, and an one-dimensional phononic crystal was designed to mask off noises of 1.5-2.5 kHz frequency which is the most sensitive to person's ear.