Clapping in delaminated sandwich-beams due to forced oscillations

Forced oscillations of delaminated composite laminates lead to non-smooth dynamic systems due to continuously developing impact-like contacts along the delamination. The primary aim of this study is to investigate a realistic model situation for delamination problems based on experiments and numerical simulation. First, the properties of lateral impacts on beam-type structures are studied, in particular in regard to the amount of energy dissipation during contact. Taking these results into account the finite element method based on beam elements is employed to simulate the stationary state of typical oscillations observed on the delaminated structure paying special attention to the dynamically developing and strongly dissipative contact. To deal with that kind of contact arising between delaminated layers, an effective technique combining a law of impact with the classical penalty method is presented. Confronting numerical results with the experimental reference provides an insight into the accuracy and robustness of the simulation technique