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

Figure 5

Two approximations of the NNM invariant manifold for the modal displacement constraint solved in respective annular domains and in phase subspace. The system parameters are set to the same as in Figure 3. The number of terms for Fourier expansion in equations (9) and (12) is set to be , and the domain of is divided into 6 or 20 equally sized elements with the number of nodes or to accurately capture the manifold geometry. A representative periodic orbit on the manifold is shown in solid line.