In-depth research is imperative for complex spatial pipelines with fluid-structure interaction. A comprehensive and universal three-dimensional semi-analytical modeling method is first established for complex fluid-conveying spatial pipelines under the base excitation with arbitrary connections and configurations under different boundary conditions. The virtual spring technology is used to connect the straight and curved pipeline segments with spatial angles and simulate boundary conditions. For a thorough analysis, the actual stiffness of the bracket-clamp system is experimentally measured for the first time. The multi-level coupling dynamic model of part, component, and system levels under actual boundary conditions is established. An efficient method for solving the fluid-structure coupling pipeline system dynamics considering the base excitation is proposed based on energy method. The mid-plane displacement function of the Fourier series is introduced and solved using the principle of modal superposition. Hammer impact modal experiments, ANSYS software and vibration response experiments are performed on spatial pipelines supported by flexible bracket-clamps; the numerical and experimental results support the semi-analytical results. The degenerate model is verified with the simple plane pipelines in other references, and the errors are less than 5 %. The proposed method exhibits broad applicability and generalizability, making it suitable for various configurations and boundary conditions.

中文翻译：

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任意航空发动机复杂空间管道的半解析建模与实验验证

对于具有流固耦合的复杂空间管道进行深入研究势在必行。首次针对基础激励下不同边界条件下任意连接和配置的复杂流体输送空间管道建立了全面、通用的三维半解析建模方法。采用虚拟弹簧技术将直、弯管道段以空间角度连接并模拟边界条件。为了进行彻底的分析，首次通过实验测量了支架夹系统的实际刚度。建立了实际边界条件下零件、构件、系统层面的多级耦合动力学模型。提出了一种基于能量法求解考虑基础激励的流固耦合管道系统动力学的有效方法。引入傅里叶级数的中面位移函数，并利用模态叠加原理求解。对柔性支架夹支撑的空间管道进行锤击模态实验、ANSYS软件和振动响应实验；数值和实验结果支持了半解析结果。简并模型与其他文献中的简单平面管道进行了验证，误差小于5%。该方法具有广泛的适用性和普遍性，适用于各种配置和边界条件。