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

庞巴迪宇航通过使用复杂的分析和制造方法，保持了高标准的先进飞机设计。这包括测量、分析和计算建模结构动力学和结构声行为的机身响应外部（发动机和湍流）和内部（子系统安装在机身内）激励。然而，为了改善机身结构的动态和振动声学性能，庞巴迪需要开发新的方法，以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，最佳是指最小化对各种激励的结构振动响应和/或限制响应的频率范围，以及最小化通过机身的声学噪声传输，同时保持尽可能低的重量。预测振动声学噪声传播的计算模型将允许应用优化策略和迭代开发过程以及虚拟测试，而无需原型制造和测试，直到最后阶段。其中包括开发机身后置发动机飞机的验证计算模型。将使用匹配物理模型上的模态测试进行验证。然后，这些模型将用于探索机身和用于安装发动机和辅助系统的支撑结构的替代结构修改。计算结构动态模型的扩展将包括声场估计。这些将用于研究不同的结构部件、材料类型、厚度和位置，以防止噪声通过机身结构和蒙皮传播。还将开发新的拓扑优化方法，重点是振动阻尼和声屏障材料的选择和放置，主要使用最小化机舱内的声场作为性能目标。

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.