【摘要】 声子晶体是近十年来提出的新课题,对声子晶体带结构的研究具有理论和应用价值。论文介绍了用平面波展开法计算二维正方点阵的固体/固体声子晶体带隙的方法,并应用于各向同性的铅柱体填充物以正方点阵排列于各向同性的环氧树脂基体中所形成的二维双组分复合体系。计算了柱体横截面是长方形时晶体的带隙,结果发现随着长方形截面的长宽比（l₁/l₂≥1时）的增加,带隙宽度逐渐减小,最后消失。更多还原

【Abstract】 Phononic crystal is a new discussion topic proposed ten years ago.The study of the phononic band structure will not only give rise to interesting new theory, but also open up variety of possible applications.We introduce the plane wave expansion method to calculate the phononic bandgap in a two-dimensional periodic system,which is composed of a square array of cylinders made of an isotropic solid（pb）embedded in an elastic isotropic host（epoxy）.On taking the cross-section of the embedded cylinders to be rectangle,we find that the width of the bandgap decreases as the ratio of the cross- section’s length to width（with l₁/l₂≥1）increases,and the band gap finally disappears completely.更多还原