ANALYTICAL MODELING AND FORCED VIBRATION ANALYSIS OF THE UNBALANCED ROTOR OF AN ELECTROMAGNETIC RETARDER

An analytical investigation has been conducted to examine the dynamic characteristics of a dual rotor system of an electromagnetic retarder.It focuses on the effects of mass imbalance in rotors and the system's inclination, which are essential for ensuring stability and optimal performance.The governing equations that describe the nonlinear dynamic response of the system under varying levels of unbalance were derived using the Lagrange method along with finite element modeling, which incorporates lumped mass and Euler beam models.The system's critical speeds and mode shapes are determined by solving an eigenvalue problem.The forced response analysis indicated that the rotational amplitude surpasses the transverse amplitude due to the overhung rotor configuration, which amplifies the centrifugal force as speed increases, influenced by different degrees of unbalanced mass.The amplitude of vibration is lower within the operational range; however, the system's tilt is critical and should be considered during the retarder design.