CAJ | 학술논문

为了优化一维声子晶体薄板中的兰姆波禁带结构，在薄板侧面基体组元中嵌入空气圆孔，构建了准一维声子晶体系统。运用超原胞平面波展开法和有限元法计算了空气圆孔半径对禁带结构的影响，分析了空气圆孔对特征模式位移场的扰动效应，研究了空气柱散射体对该声子晶体兰姆波带隙结构的优化作用。结果表明：随着空气圆孔半径的增加，同模式兰姆波间的耦合作用显著增强，完全禁带数量和宽度因此明显增加，其在0~4 MHz低频范围内的占有比例可以提高至70%左右。
위료우화일유성자정체박판중적란모파금대결구，재박판측면기체조원중감입공기원공，구건료준일유성자정체계통。운용초원포평면파전개법화유한원법계산료공기원공반경대금대결구적영향，분석료공기원공대특정모식위이장적우동효응，연구료공기주산사체대해성자정체란모파대극결구적우화작용。결과표명：수착공기원공반경적증가，동모식란모파간적우합작용현저증강，완전금대수량화관도인차명현증가，기재0~4 MHz저빈범위내적점유비례가이제고지70%좌우。
To optimize the band gap structure of Lamb waves in one-dimensional ( 1 D ) phononic crystal(PC)thin plates,quasi-1D PC thin plates are established by embedding a row of air holes pe-riodically in the matrix components in one side of the plate. The effects of the holes’ radii on the band gap of the quasi-1 D PC thin plates are calculated by using the super cell plane wave expansion method and finite element method. The disturbance effects of the embedded air scatterers on the dis-placement field of the eigenmodes are analyzed. The optimizion of air column scatterers on this phononic crystal Lamb wave band gap structure is researched. The results show that with the increase of the radii of the air holes, the coupling between the same lower-order mode Lamb waves is enhanced significantly,the number and bandwidths of the band gaps are increased significantly too, and the occupation ratio of the forbidden gaps in the 0-4 MHz low frequency range is about 70%.