基于新型MODENA方法的热声环境下薄壁结构动响应预示研究

Thin-walled structures are widely used in aerospace, aviation, etc. It is necessary to study the numerical methods of dynamic response prediction under thermo-acoustic environment for designing thin-walled structures. Modal energy analysis (MODENA) takes the pure tone modal energies of subsystems as basic unknown quantities, which can effectively predict medium and low frequency vibroacoustic response. Concerned with the dynamic response prediction under thermo-acoustic environment, the thin-walled structures are taken as the objects in this project, and three research works are mainly carried out. First, the precise MODENA modeling method for thin-walled structures under thermal environments is studied. Second, how the accuracy of MODENA results under thermal environments affected by the spatially correlated acoustic loads is investigated thoroughly. Third, the MODENA is improved to predict the dynamic responses of thin-walled structures under thermal environments which vary in time and space dimensions. Innovative advances are supposed to be achieved in the following aspects by the research: the precise MODENA modeling method for thin-walled structures under thermal environments, the mechanism of how the accuracy of MODENA results influenced by the correlation strength of acoustic loads, and the dynamic response prediction method considering the thermal environments which vary in time and space dimensions. The research can provide theoretical and technical support for the designments and dynamic strength assessments of advanced thin-walled structures in aerospace and aviation.

薄壁结构在航空航天等领域得到广泛应用，基于数值方法开展热声环境下动响应预示研究是薄壁结构设计的内在需求。模态能量法（MODENA）以子系统模态的单频振动能量为基本未知量建立动力学方程，可有效预示中低频声振响应。本项目以薄壁结构为研究对象，针对热声环境下的动力学响应预示问题，重点开展三方面的研究工作：（1）研究热环境下薄壁结构高保真MODENA建模方法；（2）研究噪声载荷空间相关性对热环境下MODENA分析精度的影响机理；（3）研究计及热环境时空分布特征、面向薄壁结构动力学响应预示的新型MODENA方法。通过本项目研究，预期将在热环境下薄壁结构精确MODENA建模方法、噪声载荷相关性对热环境下MODENA分析精度的影响机理及计及热环境时空分布特征的动响应预示方法等方面取得创新性理论成果，从而为航空航天领域先进薄壁结构的设计和动强度评估提供理论和技术支撑。

针对航空航天领域处于热声环境下的薄壁结构动响应预示问题，开展了模态能量类分析方法研究。本项目主要开展了以下三方面研究工作：（1）热环境下薄壁结构高保真建模方法研究；（2）噪声载荷相关性对分析精度影响机理研究；（3）计及温度场时变特征的薄壁结构时域动响应预示。研究进展主要体现在：（1）热效应对相关分析参数的影响，载荷空间相关性对模态能量分析精度的影响，常温下典型平板/声腔耦合系统局部响应预示，常温下舱段/声腔耦合系统局部响应预示，高温环境下结构局部响应预示。研究成果已经在先进薄壁结构的设计领域得到应用。