Research Article

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

Figure 4

Schematic diagram of the approximate expansion of NNM invariant manifold: (a) subsurface component of NNM approximation, ; (b) piecewise linear function of finite-element approximation ; (c) subsurface components of NNM approximation, , for ; (d) the resultant superposition of all subsurface components, as the approximation of this NNM manifold .
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