Crack propagation could be catastrophic, and it needs the urgent attention of the user. A cracked structure needs to be repaired or replaced at the earliest. Costs associated with the complete replacement of the part paves the way for the former option, especially in the aircraft industry. Composite materials have good directional properties in the strength and toughness compared to the conventional materials like metals, alloys and plastics. In this study carbon fibre reinforced polymer (CFRP) has been used to repair the inclined crack in aluminium alloy plate having 1.6 mm thickness. Repaired aluminium alloy specimens were subjected to fatigue load to investigate the effectiveness of CFRP. By using the ply drop technique, the strength of the damaged structure has been restored. Various options have been evaluated by conducting the design of experiment. A peeling off tendency of the CFRP patch was observed during the study. To suppress this peeling off tendency, interfacial shear stress between CFRP and the aluminium was studied more intensely rather than the fracture toughness parameters. To select the optimum configuration MCDM optimisation techniques were used and numerical solutions were validated by lab experiments.

No abstract

If the attention is not paid to the crack in a structure, then it could suddenly propagate at a rapid rate and rip apart the structures. A small crack needs urgent attention and repair since replacing the parts with a small crack is not economically feasible at all the time. Repairs were used to be carried out through rivets, welding and nut-bolts, but recently composite materials are showing promising results in this field. Since composite material are anisotropic in nature their application needs careful study about the loading pattern on the repaired structure. In this study, Carbon Fiber Reinforced Polymer (CFRP) was used as a composite material to repair Aluminium alloy specimens. These specimen were subjected to a three-point bending load to investigate the effectiveness of CFRP. By using innovative ply drop technique and design of experiment a configuration was selected to sustain three-point bending load. To suppress the CFRP’s peeling off tendency, attention was given to the interfacial shear stress rather than to the fracture toughness parameter.

No abstract

No abstract