Summary
The paper investigates the nonlinear dynamical behavior of a linear oscillator (LO) attached to an unsymmetrical nonlinear energy sink (UNES) using the frequency energy plot (FEP). The UNES considered incorporates a purely cubic stiffness element on one side of the equilibrium position and a linear restoring coupling stiffness on the other side. The obtained FEP of the LO-UNES system reveals various kinds of backbone curves. Five continuous backbones of 1:1 resonance between the LO and the UNES at different frequency levels below the LO natural frequency were obtained. This kind of UNES also has a fundamental backbone of several subharmonic resonance branches, which further assist in resonance captures during targeted energy transfer (TET) and UNES energy dissipation. Accordingly, the considered UNES design provides a more enhanced capability of TET than Type I NES, which only employs a purely cubic stiffness force.
