The inaccurate prediction of vibrations in blade-disk structures leads to frequent occurrences of failures in rotating machinery, such as air-engines. Existing methods often empirically treat the contact parameters of interfaces as globally constant and rarely consider manufacturing and assembly deviations, resulting in a deviation of prediction models from reality. This work presents a model for complex assembly structures that includes non-uniform distributions of normal contact stiffness and tangential friction coefficients at rough interfaces, while also introducing experimentally measured geometric deviations to enhance alignment with real-world conditions. Taking fir-tree blade-disk structure as an example, the accuracy of the proposed method is comprehensively verified by four measurement experiments and one modal experiment. Subsequently, the combined influence of rough interfaces and three experimentally measured geometric deviations on the overall modal characteristics of blade-disk structure are investigated, and their influencing mechanisms are revealed. The results indicate that ignoring the interface roughness and geometric deviations may significantly affect the prediction accuracy of the modal characteristics. The proposed method has great potential in the field of predicting the modal characteristics for complex assembly structures and optimizing the design of their machining and assembly processes.

中文翻译：

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叶盘的模态特性，包括粗糙界面和几何偏差


对叶盘结构振动的不准确预测导致旋转机械（例如空气发动机）频繁发生故障。现有方法往往凭经验将界面接触参数视为全局常数，很少考虑制造和装配偏差，导致预测模型与现实存在偏差。这项工作提出了一个复杂装配结构的模型，其中包括粗糙界面处法向接触刚度和切向摩擦系数的非均匀分布，同时还引入了实验测量的几何偏差以增强与现实条件的对齐。以枞树叶片盘结构为例，通过4次测量实验和1次模态实验综合验证了所提方法的准确性。随后，研究了粗糙界面和三个实验测量的几何偏差对叶盘结构整体模态特性的综合影响，并揭示了它们的影响机制。结果表明，忽略界面粗糙度和几何偏差可能会显着影响模态特征的预测精度。该方法在预测复杂装配结构的模态特性以及优化其加工和装配工艺设计领域具有巨大潜力。