Experiment analysis of impact damage of laminated composite shells

For the UIN 125B graphite/epoxy composite material with symmetric cross-ply sequences of [04/904/02]s, which is often available in airplane, the impact-induced damage initiation, propagation and damage pattern are investigated by using a drop-weight impact test. The 20-ply laminated composite cylindrical shell panels are constructed. Specimens have 6 groups with different radii of curvatures R. Each group has 7 specimens with the same dimensions. The low-velocity impact test is made for the total 28 specimens. After impact test the specimen is inspected in an X-ray chamber. The extent of the damage is measured by means of both X-ray and C-scan techniques. The influence of radius of curvatures on damage pattern and damage area are discussed. By comparison with the experiment results, the damage patterns of simulation results are in a good agreement and the damage areas of simulation ones are little larger than those of experiments.