水下压电声子晶体结构振动与声辐射特性研究

围绕国家对海上权益维护的战略需求，聚焦水下减振降噪问题，基于申请人在减振降噪和流固耦合领域的研究基础，引入压电局域共振声子晶体结构。首先，建立水下梁、板、圆柱壳声子晶体结构振动和声辐射理论计算方法，综合考虑边界条件、压电效应和流固耦合影响，与声固耦合有限元方法计算结果对比验证；其次，开展水下压电声子晶体结构减振降噪机理研究，揭示布拉格带隙和局域共振带隙共同作用机理，探明拓扑结构、基体和晶格参数、边界条件、压电效应等对于结构振动和声辐射的影响；再次，探索水下压电声子晶体结构优化设计及主动控制方法，以减小振动传递系数和声透射系数为目标，优化局域共振声子晶体拓扑结构，几何和材料参数，同时采用反馈分流电路来主动控制弹性波和声波传播；最后，通过开展振动试验、声管试验和消声水池试验，验证理论分析和数值计算成果，进一步研究振动及声辐射特性。研究成果将为新型压电局域共振声子晶体结构设计和应用奠定理论基础。

Focusing on the major strategic needs of the state in safeguarding maritime rights and interests, the issue of underwater vibration and noise reduction is addressed. Based on the applicant's research foundation in the field of structural damping and fluid-structure interaction, the piezoelectric local resonance phononic crystal structure is introduced into this subject. Firstly, considering the boundary conditions, piezoelectric effect and the influence of fluid-structure interaction, the theoretical calculation method of phononic crystal structure of underwater beams, slabs and cylindrical shells is established. The results are verified with the results of the structure-acoustic coupling finite element method. Secondly, the mechanism of vibration reduction and noise reduction of underwater piezoelectric phononic crystal structure is studied. The coupling mechanism of Bragg band gap and local resonance band gap to vibration and noise reduction is revealed. The influence of topology, matrix and lattice parameters, boundary conditions, piezoelectric materials and structural parameters on structural vibration and sound radiation is studied. Thirdly, optimization design method for underwater piezoelectric phononic crystal structure and active control method are explored. In order to reduce the vibration transfer coefficient and the acoustic transmission coefficient, we optimized the topological structure, geometry and material parameters of the local resonant phononic crystals, and the feedback shunt circuit is used to actively control the elastic wave and acoustic wave propagation. Finally, the theoretical analysis and numerical calculation results are verified by the vibration test, acoustic tube test and anechoic tank test. The research results will give a theoretical foundation for the design and application of new piezoelectric local resonance phononic crystal structure.