Impact loading in laminated composites

The aim of this study is to examine the damage and deformation (prediction, initiation and propagation), to criticize -when and which conditions they can occur- with experimental results and to compare them with finite elements results, and then comment on them. The specimens that used during the experiments are produced in Izoreel Company, and they examined with Fractovis Plus impact tester machine in different initial impact energy levels, initial velocities, and initial impactor mass. The matrix material of the specimen is made of with the mixture of CY225 epoxy with HY225 hardener resin. And the unidirectional e-glass fabric having weight of 509 g/m2 is used as reinforcing material. Specimen geometry is square with 100 mm of per edge. The sequence is in [0/30/60/90]s form. A ForTran-based 3D impact finite element code had chosen to solve both [0/30/60/90]s and other fiber orientations.The specimens tested in ternate groups. It is aimed here to examine the effects of velocity, mass and impact energy. The threshold value of the contact force that delaminations occur is examined, and also it is examined if this value could be predicted with the finite element code or not. The delamination areas and the delamination ratios are computed with a pixel-based image processing code precisely. At last, the composite laminates -that had not been experimented like the twice and third as the laminate thickness- have solved with 3D impact code, and the results have discussed.The last addition to the impact experiments is about the fiber orientations. The non-experimented specimens as [0/l5/-15/90]s, [0/30/-30/90]s, [0/60/-60/90]s, [0/75/-75/90]s had solved with finite element code, too.