Real-time reconstruction method of full-field dynamic response of rotating bladed disks

Online monitoring and health assessment of rotating bladed disks have always been a hot topic in the engineering field. However, the existing monitoring methods cannot fully perceive the vibration state of the bladed disk. Therefore, a dynamic response field reconstruction method based on blade tip timing (BTT) data is proposed to evaluate the global vibration state of the rotating bladed disk online in this paper. Firstly, a blade tip vibration decoupling method is proposed to realize the decoupling of the blade tip vibration in Cartesian coordinate system. Secondly, the blade tip vibration phase shift method is proposed, and then the reconstruction of dynamic displacement field and dynamic strain field is realized by combining the improved modal reduction/expansion method. Finally, the proposed dynamic response field reconstruction method is verified by using BTT simulation data and experimental data, and the sources of reconstruction error are analyzed. The numerical results show that the reconstruction errors of the dynamic displacement field and the dynamic strain field are both less than 10% except for the area near the nodal diameter. The experimental results also show that the dynamic strain reconstruction error is less than 15% due to the influence of test noise. The response field reconstruction method proposed in this paper can provide sufficient data support for the online monitoring and fatigue life prediction of the rotating bladed disks. In particular, it can provide strong support for the application of digital twin technology in the field of structural health monitoring of the rotating bladed disks.