中文摘要：

选用非金属材料塑料和硅橡胶,组合成一维二元声子晶体匀直杆状结构.通过单一改变结构中非金属材料塑料的密度或者硅橡胶的密度,寻找单一材料密度变化与声子晶体杆禁带特性的关系.结果表明：当选取塑料密度为1190kg·m-3、硅橡胶密度为1300kg·m-3,晶格常数为0.3m,两种材料组份比相同时,一维二元非金属塑料/硅橡胶声子晶体存在低频禁带带隙,第1禁带起始频率为43.07 Hz、禁带带宽为33.09Hz,第2禁带起始频率为99.84Hz,第2禁带带宽为52.49Hz;当单一改变塑料的密度,随着密度由小到大线性增加,结构第1带隙的起始频率由66.58Hz逐步减小到34.04Hz;第1带隙的截止频率为76.17Hz,保持不变,带隙宽度展宽;当单一改变材料硅橡胶的密度时,随着材料硅橡胶的密度由小到大线性增加,第1带隙的带宽由109.894HZ减小为18.3748Hz.对于一维二元非金属型声子晶体,选用密度更小的非金属材料与密度更大的非金属材料组合,更容易获得低频宽带带隙.另外,基于密度变化的同时还可以通过改变结构晶格常数的取值来获得更为理想的声子晶体禁带带隙.

英文摘要：

Straight rod structure of one - dimensional binary phonon crystal is designed with nonmetalplastic and silicon rubber. The paper presents the author＇ s attempt to probe fro the law governing the influ-ence of density change on the forbidden band properties by changing the density of plastic or rubber onlyThe result shows that phononic crystals of one - dimensional binary non - metal show forbidden properties,the starting frequency of the first forbidden band is 43.07 Hz, wideband is 33.09Hz, the starting frequen-cy of the second forbidden band is 99.84 Hz and wideband is 52.49 Hz when plastic density being 1190kg· m-3 and silicon density being 1300 kg· m -3. When only increasing plastic density, the startingfrequency of the first band gap decreases from 66.58 Hz to 34.04 Hz. The stopping frequency of the firstband gap is 76.17Hz and band gap broadens when frequency remains constant. When only changing thedensity of rubber, the bandwidth decreases from 109. 894HZ to 18. 3748 Hz with the increasing of rubberdensity. For one - dimensional binary non - metallic phononic crystal, low frequency broadband band gapis easier to obtain when non - metal materials of lower density are combined with metal materials of higherdensity. In addition to change in density, variation can also change the structure of the lattice constant val-ues to get more ideal phonon crystal forbidden band gap.