Experimental observation of localisation in a symmetric structure with non-smooth nonlinearities

In this work we investigate experimentally the localisation of energy that occurs in
a symmetric structure composed of two weakly coupled identical beams impacting against bilateral rigid stoppers. The nonlinear modes of the underlying simplified model display localised solutions bifurcating from the homogeneous out-of-phase mode. In the range of frequencies where in-phase and out-of-phase nonlinear modes can interact, four stable branches are observed both numerically and experimentally, two of which consist of localised vibrating states.