An experimental study on the Charpy impact response of cracked aluminum plates repaired with GFRP or CFRP composite patches

In this study, edge-cracked aluminum plates repaired with one-sided composite patches were investigated experimentally for their response to Charpy impact test. Two different materials were used for composite patches, in one the reinforcement was woven glass–fibres while the other had woven carbon fibres as the reinforcement. Further, in each case, two lay-ups were used, viz. 3-ply and 5-ply. Also, the aluminum specimens had edge-cracks of three different lengths. In each case, the energy absorbed during the impact test, when the specimen had a crack of known length and reinforced with patches, was determined and compared with the energy absorbed during impact of the corresponding specimen without crack. It was observed that for a given crack length, the 5-ply patch of carbon fibres performed better than all other patches. For example, when the ratio of the crack length to the specimen width, i.e. l/w is 0.5, the percentage of the absorbed energy for the specimen repaired with 5-ply carbon fibre patch is 2-times as compared to the specimen repaired with 5-ply glass–fibre reinforced patch.