Host: The Japan Society of Mechanical Engineers
Name : Dynamics and Design Conference 2018
Date : August 28, 2018 - August 31, 2018
The effectiveness of a dynamic absorber for self-excited vibration has been known for several years. However, in the case of self-excited vibration, the operating mechanism of a dynamic absorber is still poorly understood. In this paper, a simple and fundamental model with three degrees of freedom (DOFs), which is consisted of a two-DOF system with an asymmetric stiffness matrix and a single dynamic absorber, are considered and the operating mechanism is investigated. As an analytical tool to clarify the operating mechanism, a new type of complex modal analysis is developed for accurately evaluating the energy for each mode. By applying the new method, the damping matrix can be diagonalized exactly in addition to the symmetric mass and stiffness matrices of the system, and the equation of motion for a multi-DOF system can be converted into modal equations for a single-DOF system in the form of real second-order differential equations. From the modal equation, we derive the approximate solutions of the coupled vibration of two modes. However, these approximate solutions are not accurate due to the other modal coupling. In this paper, we derive the more accurate approximate solutions by considering effects of modal coupling.
