Edge impact damage scenario on stiffened composite structure

International audience; Low velocity / low energy edge impact and almost-static experiments have been carried out on carbon fiber reinforced plastic (CFRP) structures. A drop-weight testing machine was used to impact four different UD laminates at 10, 20 and 35 J impact energy levels. In parallel, an almoststatic study has been conducted in order to compare its results with the impact one. Compression after impact tests will supply the residual behavior afterwards. The impact results show that the static and dynamic behaviors are different. A simplified analytical impact model is provided trying to explain the difference between static and dynamic edge impact regardless the stacking or impact energy. It actually well represents the dynamic and static initial stiffness and the crushing plateau. The fiber properties control the initial impact stiffness. In addition, regardless of the impact energy and stacking, a specific "crushing plateau" phenomenon appears. In the almost-static indentation case the properties of the matrix control the initial indentation stiffness. The experimental results will be compared to a numerical model in order to simulate the impact and compression after impact damage.