柔性粘弹性边界条件夹层板-声腔耦合系统中频域声振特性研究

Using viscoelastic boundary condition constraints sandwich panel structure，this kind of boundary containing viscous damping could be used to absorb vibration energy and it has a great value in the field of noise reduction engineering. At present, most researches are limited to use traditional Kelvin-Voight linear damping model to describe viscoelastic boundary condition. However, the Kelvin-Voight model can't reflect the nonlinear damping of real working viscoelastic boundary condition. Hence, this project firstly does the vibration theoretical and modal experimental study based on the nonlinear dynamic theory and matrix perturbation method for sandwich panel with flexible viscoelastic boundary supports and proposes a kind of experimental identification method to estimate non-proportional damping matrix of panel structure boundary condition by incomplete modal experimental parameter. This project establishes a correct mechanics and mathematical model to describe real working of the viscoelastic boundary condition. Secondly, this project establishes a dynamics theory and numerical model of an acoustic cavity coupled with a flexible viscoelastically supported sandwich pane based on the hybrid finite element-wave function method. Then, this project designs experimental device on the basis of theoretical model. Finally, according to the numerical simulation and experimental analysis, this study reveals the influence rule of viscoelastic boundary much material physical properties, sandwich panel constitutive parameters, acoustic structure parameters on vibro-acoustic characteristics in mid-frequency and also clarifies the damping characteristic of viscoelastic boundary impact on the vibro-acoustic coupled mechanism. The research results can provide a theoretical reference to explore the potential of boundary conditions for internal noise suppression and provide a scientific criterion to optimization the acoustic performance of interior compartment in automobile and aerospace ride tools.

采用粘弹性边界条件约束夹层板结构，其粘滞阻尼可吸收振动能量，对抑制封闭空间噪声有极大的应用价值。针对当前研究局限于用传统Kelvin-Voight线性阻尼模型描述粘弹性点支撑边界条件，不能反映真实工况粘弹性边界非线性阻尼问题。本项目基于非线性动力学理论和矩阵摄动法，对四边粘弹性约束夹层板进行振动理论和模态试验研究，提出不完备模态估计粘弹性边界阻尼矩阵的实验识别方法，构建符合实际工况的粘弹性边界力学和数学模型。继而采取混合有限元-波函数法建立柔性粘弹性支撑夹层板-声腔耦合系统动力学理论和数值模型。在此基础上设计实验装置，通过数值仿真和试验分析，揭示粘弹性边界多种材质物理属性、夹层板本构参数、声腔结构参数对封闭声腔中频声振特性影响规律，阐明粘弹性边界阻尼特性对结构-声腔耦合作用影响机制。研究成果可为挖掘边界条件潜力抑制内部噪声提供理论参考，并为汽车、航空航天乘坐工具腔室声学优化提供科学判据。

板结构边界条件对声振耦合特性有着重要影响，实际工程领域结构-声腔系统普遍采用粘弹性边界条件，(边界含有)其粘滞阻尼可吸收振动能量，对减振降噪有极大的应用价值。本项目针对现有板结构经典边界条件不考虑边界阻尼的不足， 基于动力学理论、有限元仿真和实验研究，对四边粘弹性支撑板结构振动响应和复杂边界条件下夹层板结构振动-声腔耦合机制展开了研究。设计了实验装置，针对四边粘弹性支撑板、固支板分别进行模态测试，分析粘弹性边界对固有频率和损耗因子的影响，采用等效弹簧振子构建粘弹性支撑边界力学模型，提出新的位移函数形式，运用Rayleigh-Ritz方法求解矩形板横向振动时的固有频率。并基于波函数法，提出完备的波函数序列，通过半理论半数值求解分别得到有限大板结构、声腔响应。针对有限大夹层板，建立了其在四边固支、简支边界条件下的声波激励动力学模型，利用模态叠加法推导了夹层板结构动态响应和隔声量理论计算公式。讨论了夹层板本构参数、芯层材料布局方式、边界条件对隔声特性的影响规律，阐明结构-声腔振型耦合机制。本研究成果可为认识粘弹性边界条件对于结构振动响应影响规律奠定了理论基础，同时对于分析复杂边界条件夹层板-声腔系统耦合机制提供了分析框架。板结构边界采用粘弹性边界在交通工具、航空航天、建筑等领域应用普遍，具有巨大的商业价值。本研究成果为实际工程预测复杂边界条件板结构-声腔耦合系统声振特性提供参考依据。. 课题组在项目资助下已经发表学术论文7篇，待发表2篇，申请了1项专利，培养了硕士研究生3名。项目投入20万元，支出15.424万元，各项支出基本与预算相符合。剩余经费 4.5760万元， 剩余经费计划于本项目研究后续支出。