Numerical and experimental study of nonlinear localization in a flexible structure with vibro-impacts

In this work a numerical and experimental study of nonlinear motion confinement phenomena in a nonlinear flexible assembly with vibro-impacts is carried out. The assembly consists of two coupled cantilever beams whose motion is constrained by rigid barriers. In the theoretical model the impact nonlinearities are simulated by clearance nonlinearities with steep stiffness characteristics; special care is taken to model energy dissipation due to inelastic impacts. The theoretical results confirm that the vibro-impact system possess motion confinement properties. Both transient and steady state motions are studied, and it is shown that under certain conditions the vibrational energy of the system is passively confined to only one of the two beams. These essentially nonlinear responses exist inspite of direct coupling between the two beams, and have no analogs in linear theory. The experimental results confirm the theoretical predictions both in the transient and steady state regimes. The passive nonlinear motion confinement phenomena reported in this and previous works can be utilized to enhance the controllability of flexible structures with symmetries, and to improve current shock and vibration isolation designs of such systems.