Amplitude modulated motions in a two degree-of-freedom system with quadratic nonlinearities under parametric excitation: experimental investigation

Abstract

We conducted an experimental investigation of amplitude modulated response of a two degree-of-freedom mechanical structure with quadratic nonlinearities to parametric excitation. The linear natural frequencies of the system were tuned so that they were approximately in the ratio of two-to-one, and the excitation frequency was in principal parametric resonance with the first mode. We observed periodically amplitude-modulated motions and chaotically amplitude-modulated motions.