This paper proposes a model-based approach for identifying rotordynamic parameters using full spectrum. First, for developing a mathematical model a cracked shaft system with an offset-disc integrated with an active magnetic bearing (AMB) is considered. Moreover, external viscous and internal (rotating) damping is considered in the mathematical model to analyze their effect on the dynamics of the cracked rotor system. Subsequently, an identification algorithm is developed based on the proposed mathematical model to estimate the critical parameters of the model with the help of displacements and AMB currents obtained from full spectrum analysis. Eight parameters, such as the external and internal damping, translational as well as rotational additive crack stiffness, disc eccentricity and its phase, and AMB parameters, are the main parameters affecting the dynamic behaviour of a rotor system estimated. To overcome the practical difficulty in the measurement of rotational displacements during the identification, a gyroscopic dynamic reduction scheme is used to remove the rotational degrees of freedom. The developed algorithm is tested against various random noise in responses and modelling or bias errors in physical parameters to check the sensitiveness and robustness of the model as in the real case.

中文翻译：

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装有主动磁轴承的裂纹转子系统中多个故障参数的动态分析和识别：基于物理模型的方法

本文提出了一种基于模型的方法，用于使用全谱识别转子动力学参数。首先，为了开发数学模型，考虑了带有集成有主动磁轴承 (AMB) 的偏置盘的裂纹轴系统。此外，在数学模型中考虑了外部粘性和内部（旋转）阻尼，以分析它们对裂纹转子系统动力学的影响。随后，基于所提出的数学模型开发了一种识别算法，以借助从全谱分析获得的位移和 AMB 电流来估计模型的关键参数。八个参数，例如外部和内部阻尼、平移和旋转附加裂纹刚度、盘偏心及其相位和 AMB 参数，是影响估计的转子系统动态行为的主要参数。为克服识别过程中旋转位移测量的实际困难，采用陀螺动态折减方案去除旋转自由度。开发的算法针对响应和建模中的各种随机噪声或物理参数中的偏差进行了测试，以检查模型的灵敏度和鲁棒性，就像在真实情况下一样。