【作者】 陈圣兵；

【导师】 韩小云；

【作者基本信息】 国防科学技术大学 ， 机械工程， 2009， 硕士

【摘要】 本文对压电材料在可调带隙声子晶体中的应用进行了有益的探索。将振动控制中的压电分流阻尼技术引入到声子晶体中,设计了贴片式压电声子晶体梁结构。研究了电路参数对梁带隙的调控,并分析了带隙形成和带隙调控的机理。进一步对二组元嵌入式压电声子晶体梁、轴和板结构的带隙特性进行了探索,从电极状态、压电常数和极化方向等方面研究了压电效应对带隙的影响。主要研究结论包括:(1)对贴片式和嵌入式压电声子晶体带隙特性的理论仿真研究表明,在声子晶体结构中引入压电材料可以设计带隙特性可调的声子晶体,而且调节简便。(2)类似于局域共振带隙,在压电声子晶体中存在电磁振荡带隙,该带隙频率与压电片外接分流电路的固有电磁振荡频率强相关,且比该电磁振荡频率稍高。(3)压电材料调节声子晶体带隙特性的途径是:利用外接分流电路的电磁特性来改变压电材料的等效弹性模量,进而改变声子晶体内部材料组分之间的弹性模量对比,最终改变声子晶体的带隙性能。(4)具有电磁振荡特性的外接分流电路对声子晶体带隙性能的调节效果更加显著,而且压电材料为各向异性材料,不同的极化方向对声子晶体带隙性能的调节会有差别。本文研究工作对带隙可调的声子晶体设计具有指导意义。更多还原

【Abstract】 In the thesis, some favorable explorations are conducted in the application of piezoelectric materials in phononic crystals (PCs). By introducing piezoelectric shunting techniques into PCs, a type of phononic beam on which piezoelectric patches are periodically mounted is designed. The active control of the beam’s band gaps by properly adjusting parameters of shunting circuits has been investigated. Furthermore, the gaps’formation and control mechanisms are also researched. The band gaps properties of phononic beams, shafts and plates with piezoelectric materials embedded in are also investigated, then the influences of piezoelectric effect to band gaps are analyzed from the perspectives of electrodes’status and piezoelectric constant and polarized direction.The conclusions are drawn as follows:(1) By the theoretical analysis and numerical simulation of PCs with piezoelectric materials in mounted type or embedded type, the approach that introducing piezoelectric materials in PCs to design PCs whose band gaps can be actively tuned is proved reasonable, moreover, the process is simple and convenient.(2) Similar to the locally resonant PCs owning locally resonant band gaps, the PCs with electromagnetic-oscillation circuits also have electromagnetic-oscillation band gap. The frequencies of the gap are related to the eigenfrequency of piezoelectric shunting circuits, but a little higher than it.(3) The approach to tuning PCs’band gaps using piezoelectric materials is using the shunting circuits’electromagnetic properties to adjust equivalent elastic modulus of the piezoelectric materials, and actively tune the discrepancy of elastic modulus between different components in the PCs, which finally lead to the changes of band gaps’properties.(4) The band gap’s tuning effects are more remarkable when its shunting circuits own electromagnetic loops. Because piezoelectric materials are elastic and electromagnetic anisotropy, the tuning abilities of PCs with different polarized directions will differ.The work in the thesis can be used to guide the design of PCs whose band gaps can be actively tuned.更多还原