Measurement of dynamic parameters in laminated stator core based on ultrasonic signals

Abstract

The stator core is a critical component in marine propulsion motors and shipboard drive systems, directly influencing operational efficiency, stability, and service life. Accurate measurement of its dynamic parameters—Young’s modulus and loss factors are essential for vibroacoustic performance evaluation. This study introduces an ultrasonic measurement method to characterize the axial and radial dynamic parameters of laminated stator cores. Wave velocity and attenuation were extracted via cross-correlation and signal energy analysis from homogeneous shells, reduced-scale bar samples, and a full-scale stator core. Results reveal significant anisotropy, with axial Young’s modulus considerably lower than in the radial direction due to interfacial compliance and wave scattering within the laminated structure. The loss factor, consistently measured between 0.06–0.12, further confirms substantial energy dissipation in the layered composite. Additionally, the strong agreement between the simulated and experimental modal frequencies validates the accuracy of the dynamic parameters measured via the ultrasonic method. The proposed contact approach improves measurement accuracy and efficiency, providing a reliable basis for marine motor condition monitoring, fault diagnosis, and low-noise design of ship propulsion systems.