Fuselage structural dynamic and vibro-acoustic analysis, modeling, and optimization

庞巴迪航空航天公司通过使用复杂的分析和制造方法，保持了先进飞机设计的高标准。这包括对机身在外部(发动机和湍流)和内部(安装在机身内的子系统)激励下的结构动力学和结构声学行为进行测量、分析和计算建模。然而，为了改善机身结构的动态和振动-声学行为，庞巴迪需要开发新的方法来帮助确定最佳配置和材料选择。将要开发的计算建模和优化工具将用于确定最佳机身设计。在这种情况下，最佳是指使结构对各种激励的振动响应最小化和/或限制响应的频率范围，以及在保持尽可能最低的重量的同时最小化通过机身的声音噪声传输。预测振动-声学噪声传播的计算模型将允许应用优化策略以及迭代的开发和虚拟测试过程，直到最后阶段不需要原型制造和测试。其中包括开发安装在机身上的后置发动机飞机的经过验证的计算模型。验证将在匹配的物理模型上使用模态测试进行。然后，这些模型将用于探索用于安装发动机和辅助系统的机身和支撑结构的替代结构修改。计算结构动力学模型的扩展将包括声场估计。然后，这些将被用来调查不同的结构部件、材料类型、厚度和位置，以防止噪音通过机身结构和蒙皮传播。还将开发新的拓扑优化方法，重点放在减振和声屏障材料的选择和布置上，主要是以最小化舱室内的声场为性能目标。

Bombardier Aerospace maintains a high standard of advanced aircraft design through the use of sophisticated analysis and manufacturing methods. This includes measurement, analysis, and computational modeling of the structural dynamics and structure-borne acoustic behavior of the fuselage in response to external (engines and turbulence) and internal (sub-systems mounted within the fuselage) excitation. However, to improve the dynamic and vibro-acoustic behavior of the fuselage structure, Bombardier needs to develop new methodologies that will help define optimum configurations and material selection. The computational modeling and optimization tools to be developed will be used to define optimum fuselage designs. Optimum, in this case, refers to minimizing the structural vibration response to various excitations and/or limiting the frequency range of the responses as well as minimizing acoustic noise transmission through the fuselage while maintaining the lowest possible weight. Computational models that predict vibro-acoustic noise transmission will allow for the application of optimization strategies and an iterative process of development and virtual testing without the need for prototype fabrication and testing until the final stage.The proposed project includes three main objectives. These include the development of verified computational models of a fuselage mounted rear-engine aircraft. Verification will take place using modal testing on a matching physical model. The models will then be used to explore alternative structural modifications to the fuselage and support structures used to mount the engines and auxiliary systems. Extension of the computational structural dynamic model will include acoustic field estimation. These will then be used to investigate different structural components, material types, thicknesses, and placement to prevent acoustic noise from being transmitted through fuselage structures and skin. New topology optimization methods will also be developed focused on vibration damping and acoustic barrier material selection and placement primarily using minimization of the acoustic sound field within the cabin as the performance objective.