南京大学学报(自然科学版) ›› 2012, Vol. 48 ›› Issue (5): 531536.
刘聪,徐晓东,王敬时,刘晓峻
Liu Long,Xu Xiao Dong**,Wang Jin Sh:,Liu Xiao一Jun
摘要: 近年来,Lamb波在声子晶体板中的传播特性受到了研究者的广泛关注.在前人的研究基础上,木文利用传统的一维声子晶体板构建了三明治型声子晶体复合板模型,并运用有限元法研究了三明治型复合板的上下覆盖层对Lamb波禁带分布的影响.所谓三明治型声子晶体复合板即通过在传统一维声子晶体板的上下表面对称覆盖
一定厚度的纯材料板得到.利用该模型,数值分析了不同三明治型复合板中Lamb波的传输谱,计算结果证明,当上下两覆盖层的材料为硬材料时,覆盖层对禁带分布的影响巨大,禁带随着覆盖层变厚迅速消失;另一方面,若上下两覆盖层为软材料构成时,可以发现一个新禁带的形成,并且随着覆盖层厚度增加逐渐趋于与原禁带合并.而对于覆盖层为中等硬度材料的情况,覆盖层对禁带分布的影响介于软材料和硬材料之间.研究结果表明:当声子晶体的结构保持不变时,该声子晶体的禁带分布可通过构建相应的三明治模型进行调节.
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