The 2011 issue of Nonlinear Dynamics presents articles on stability of non-linear dynamic structures and systems. Alijani and co-researchers investigate geometrically nonlinear vibrations of rectangular plates with Functionally Graded Materials (FGM) in thermal environments via a multi-modal energy approach. Demeio and co-researchers investigate the primary non-linear resonance response of a one-dimensional continuous system, which can be regarded as a model for semiinfinite cables resting on an elastic substrate reacting in compression only, and subjected, to a constant distributed load and to a small harmonic displacement applied to the finite boundary. Stoykov and Ribeiro investigate the geometrically non-linear periodic vibrations of beams with rectangular cross section under harmonic forces using a p-version finite element method. Krylov and co-researchers investigate the feasibility of two-directional switching of an initially curved or prebuckled electrostatically actuated micro-beams using a single electrode fabricated from the same structural layer.