“…These new frontiers are covered in this Special Issue by addressing problems related to global bifurcations [19], stability of nonlinear normal modes [20], localization of symmetric systems [21], identification of backbone curves [22], modal energy exchange [23], vibro-impact [24], internal resonance [25] and hysteretic systems [26]. Gyroscopic effects are also addressed for continuous rotor systems [27], and the nonlinear dynamics and stability of fiber reinforced polymer structures [28], and plates with nonlinear fractional damping [29], are also investigated. The question of tailoring the nonlinear response of a mechanical system is also studied from a theoretical perspective [30].…”