Influence of skin damage on the indentation behavior of sandwich beams

An analytical investigation of the problem of the indentation of composite sandwich beams with partially delaminated face sheets is presented in this paper. A model has been formulated that represents the damaged face as an elastic beam resting on an elastic-perfectly plastic foundation. The results show the influence of the damaged area on the behavior of the system: the indentation load is lower than that of an intact beam and the reduction is more important on increasing the number of delaminations or their lengths; the critical load for progressive yielding of the core is also affected by the presence of a damaged area whose influence decreases on increasing the size of the plastic zone