Host: The Japan Society of Mechanical Engineers
Name : Dynamics and Design Conference 2022
Date : September 05, 2022 - September 08, 2022
Nonlinear characteristics of two DOF Duffing oscillator with fifth order term are investigated. The system used in this study has mass and stiffness proportional dampings simultaneously, and two combinations of stiffnesses that have same natural frequencies. In our previous reports for the same system, nonlinear characteristics were qualitatively studied using frequency response curves of modal coordinates. However, the quantitative criterion of the nonlinear characteristics is desirable. For one DOF Duffing oscillator, single backbone curve symbolically describes many frequency response curves for the various amplitude of the response. In this study, the coefficients of the backbone curves are evaluated and compared with the parameters of the system. The calculated examples show that the coefficients were successfully identified for the modal amplitudes with softening characteristics. However, for the case that the modal amplitudes had the softening and hardening characteristics, the backbone curves went out of the frequency response curves. The parameters of backbone curves were independent from the ratio between mass and stiffness proportional dampings.
