A crack is one of the most dangerous faults in rotors of key rotating machinery. In order to make reasonable maintenance, crack localization for rotors under operational conditions is very important and full of challenges. Focusing on crack localization in rotating rotors, a new crack localization method for stepped rotors based on Bayesian fusion of multiscale superharmonic characteristic deflection shapes (SCDSs) is proposed. The non‐linearity induced by cracks is utilized to eliminate the interference of stiffness reduction by steps in the rotor, and the noise‐robustness issue is tackled by casting the SCDSs into multiscale SCDSs with multiscale space theory. Moreover, Bayesian fusion is applied to the multiscale SCDSs to derive a new damage index to localize cracks. Numerical and experimental investigations are conducted to validate the proposed method. The results indicate that the proposed method is effective, accurate and robust for single or multiple crack localization in stepped rotors, and thus, it has a great potential in practical applications.

中文翻译：

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基于多尺度超谐特征挠度形状的贝叶斯融合的阶梯转子裂纹局部化

裂纹是关键旋转机械转子中最危险的故障之一。为了进行合理的维护，在运行条件下转子的裂纹定位非常重要，并且充满挑战。针对旋转转子的裂纹局部化问题，提出了一种基于多尺度超谐特征偏转形状（SCDSs）贝叶斯融合的步进转子裂纹局部化新方法。利用裂纹引起的非线性来消除转子中阶梯式刚度降低的干扰，并通过采用多尺度空间理论将SCDS转换为多尺度SCDS，从而解决了噪声鲁棒性问题。此外，将贝叶斯融合应用于多尺度SCDS，以得出新的破坏指数来定位裂纹。进行了数值和实验研究，以验证所提出的方法。结果表明，该方法对于步​​进转子中单个或多个裂纹的定位是有效，准确和鲁棒的，因此在实际应用中具有很大的潜力。