双局域共振机制声子晶体带隙特性研究

提出了一种双局域共振机制,结合有限元法对该机制声子晶体结构的带隙生成机理和带隙的影响因素进行了深入分析研究。2个刚性质量体互为刚性边界和振子,由此产生了2个可以互相转化的局域共振单元。双局域共振结构的带隙位置由2个等效单自由度系统的固有频率共同决定,带隙的宽度与2个质量体密度、内振子半径、弹性介质的弹性模量密切相关。研究发现,2个质量体密度差别越大、弹性介质弹性模量越高,带隙的宽度就越大。该机制在一定程度上削弱了基体与振子的紧密耦合关系,该结构具有较大的带隙变化范围,极大地增大了带隙的宽度,为宽频声子晶体结构的研究提供了新的思路。

Study on the Phononic Crystals Bandgap Properties of Double Local Resonance Mechanism

The paper puts forward a kind of double local resonance mechanism. Combined with finite element method (FEM), the author makes a thorough analysis and research on phononic crystal structure of the double local resonance mechanism about formation mechanism and influence factors. Two rigid bodies are rigid boundary and oscillator to each other, so two local resonance units which can convert each other engendered. The natural frequency of two equivalent single degree of freedom system codetermine the local resonance structure of the band gap position, the width of band gap closely related to oscillator within two quality volume density, radius, the elastic modulus of elastic medium. The study found that the two masses density difference, the greater the elastic medium the higher modulus of elasticity, the greater the width of band gap. The mechanism decouples the relationship of matrix and oscillator to some extent,which makes the phononic crystal structure has larger band gap range and greatly increases the width of band gap,providing a new way for broadband phonon crystal structure research.