Abstract:

The paper deals with the mechanical modeling of a sensor concept in the framework of Motion Induced Eddy Current Testing (MIECT). The system consists of a magnet arrangement with two axially magnetized cylinder magnets, which are fixed to a shaft, driven by a motor with a constant angular velocity. A pick-up coil, assembled around the magnet arrangement and fixed to the sensors framework, measures the magnetic flux varying in time. The mechanical behavior of this experimental setup is analyzed using analytical and numerical methods. The main conclusions concerning the systems behavior are made with the asymptotic method.The investigations based on methods of Bogoliubov & Mitropolski show, that the main contribution to the solution is given by the first fundamental harmonic. The exact equation of motion is integrated numerically. The results of the theoretic investigations are compared with experimental data.

Keywords: Nondestructive testing; unbalanced rotor; nonlinear oscillations; parameter identification; eigenfrequency; asymptotic methods.