Influence of the laminate thickness in low velocity impact behavior of composite material plate

The low velocity impact behavior of carbon fiber-epoxy matrix laminates has been studied by experimental drop dart tests. The considered composite laminate is characterized by two different stacking sequences. Plates of three different values of the laminate thickness have been tested both by quasi-static and dynamic impact loading. The force-displacement curves, obtained during tests conducted with different impact velocities, are superimposed in order to point out that the considered material, in the considered loading conditions and impact velocity range, has no sensitivity to strain-rate effect. The energy absorption capability is studied with respect to the different laminate lay-ups. Finally some considerations are developed on the dependence of the first damage force and maximum force values, of the saturation energy and of the plate flexural stiffness with respect to the laminate number of layers variable. (C) 2003 Elsevier Science Ltd. All rights reserved.