波纹芯体金属夹层板的声透射机理及透射损失计算方法研究

Metallic sandwich plates with corrugated cores are used extensively in the high speed transportation-engineering field for their higher specific strength and stiffness than those of an homogeneous type. Efective methods for numerical modeling of sound transmission through this kind of structures and effcient tools for computing the sound transmission loss (STL) with an acceptable accuracy and execution time, are needed by the designers of high speed transportation systems to predict their interior noise levels at early design stage and to perform structural optimization.To achieve the targets, it is necessary to obtain a detailed understanding of the physical mechanisms of sound transmission through sandwich plates with corrugated cores. ..The proposed project starts from a theoretical analysis of sound transmission through metallic sandwich plates with corrugated cores.Initially a 2D analytical model of two parallel plates connected by a single flexible stiffner is developed with consideration of structural-acoustic coupling between elastic structures and two air-cavities formed by the plates and core. The STL is calculated for different cavity sizes and structural parameters, to understand the effect of the structural-acoustic coupling on sound transmission, and also the relative importance of sound transmission through the core structure and that through the air cavities. Secondly, on the basis of analytical studies and within the spectral finite element (SFE) context,the methodology for numerical modelling of sound transmission through sandwich plates is developed specifically for typical core topologies, and the associated computational procedure is established for calculating STL values over a wide frequency range. Thirdly, STL measurements of specially-fabricated sandwich plates with corrugated cores using the sound insulation measurement method for small-size strutcures are conducted to verify the proposed analytical approach and to validate the numerical model for STL computation. Finaly, a sensitivity analysis of STL with respect to the geometric and acoustical parameters of corrugated cores is performed, to determine major influencing parameters of the core on STLs of the sandwich plate, and further to establish the structural optimization method and associated computational procedure for maximizing the STL over a wide frequency range under constraints of structural weight and specific bending stiffness...The research work to be completed through this project is expected to enrich the sound insulation theory of complicated structures,and the results would be meaningful in guiding the leightweight and interior acoustic comfort designs of modern high speed transportation systems.

以波纹板为芯体的全金属夹层板结构具有比强度和比刚度高的优点, 广泛应用于现代高速载运工具。载运工具的内部噪声水平预估和夹层板的结构优化迫切需要建立其声透射损失计算的有效数值方法,而深入认识其声透射机理是实现这些目标的关键。 .本项目首先构建由单一筋板连接的夹层板双声腔声-固耦合二维解析模型，分析连接芯体和面板与其形成的闭合空腔间结构-声学耦合机制及其对构件声透射的影响，识别结构路径传声和空气路径传声的相对贡献。然后，建立适用于典型波纹构型的有限尺寸夹层板声透射分析的谱元法理论及建模方法，以计算整体结构的声透射损失。对机理分析的正确性和谱元法数值计算的准确性，通过小尺寸构件的隔声测量进行实验验证。最后，通过灵敏度分析，识别影响夹层板声透射损失的主要芯体参数,并据此建立结构优化设计方法。.项目研究成果将丰富复杂结构的隔声理论，对高速载运工具的轻量化和车（舱）内声学舒适性设计具有实际指导意义。

自本项目开始执行以来，通过理论建模、数值仿真和实验分析，开展了基于声-固耦合理论的波纹芯体金属夹层板结构入射声场作用下经结构路径和空气路径传声机理的研究，给出现有夹层板声透射计算模型中的“筋板声学透明”假设的适用条件；并基于谱单元法及能量变分原理分别建立了用于结构声学性能快速优化和结构-声学耦合系统振-声学响应计算的数值计算高效方法；进行了夹层板声透射损失对结构材料拓扑参数的灵敏度分析，以此为基础建立了振-声学性能优化方法；为验证振-声学性能的优化结果，进行了典型波纹芯体金属夹层板隔声性能的实验研究。项目全面达到了预期目标，完成了预期的研究任务，共发表论文18篇，其中在SCI期刊发表和完成清样校稿的论文11篇，获得1项软件著作权，申请发明专利1项，至今共有3名博士生和3名硕士生参加本项目的研究，其中1名博士生和3名硕士生完成了学业，另2名博士生正在撰写学位论文。