Study on the salvage of an axial penetrated crack on the composite cylindrical shell with a reinforced open hole

A study on the salvage of a composite cylindrical shell with a reinforced open hole, containing an axial penetrated crack, was carried out. The finite element method was used to establish an analysis model for the original structure with defects and employed to analyze its compressive buckling strength and model. The relationship between the length of the penetrated crack and the buckling strength of the cracked cylindrical shell was established. This buckling strength was compared with that of a shell with no crack. Naturally the results show that the buckling strength of the cracked cylindrical shell becomes lower than that of the cylindrical shell without crack. As the length of the crack exceeds a certain range, the buckling region is shifted from the area around the hole to the area around the crack, resulting in a sharp drop of buckling strength. Proper repair should be carried out to salvage the structure by improving the shear load carrying capacity in cracked region of the shell. After repair, a buckling analysis was again carried out and it was found that, the buckling mode of the repaired shell was resumed to that of the shell without any crack, with a slight increase in buckling strength. This illustrates the salvage method is effective.