DYNAMIC STABILITY OF NONLINEAR SDOF SYSTEMS FOCUSING ON THE MOVEMENT OF OSCILLATION CENTER AXIS

Abstract

 In this study, the dynamic stability of nonlinear single-degree-of-freedom systems with the movement of oscillation center axis (drift) is theoretically and analytically investigated to understand basic dynamic response characteristics of structures in the region of reduced restoring force. Specifically, The response magnification factor of the drift to forced frequency is derived and validated by numerical analysis. As a result, the theoretical value calculated from the response magnification factor was reproduced by the analysis. In addition, it was confirmed that the response diverges to one side rapidly at the singularity on the drift-frequency relation derived from the response magnification factor. Thereby it was suggested that the amount of drift on the singularity may be an important indicator for the dynamic stability of structure systems.