Research Article

Nonlinear Normal Modes in a Two-Stage Isolator Using a Modified Finite-Element Galerkin Method

Figure 11

Top plots: the NNM invariant manifold approximations and five representative periodic motions in the phase space of physical coordinates , for , , , and . Bottom plots: the corresponding NNM invariant manifold approximations and periodic motions in the phase space of modal coordinates, for , , , and .