抄録
Composite materials, especially carbon fiber reinforced plastics (CFRP), have been widely used in the airplane primary structures like wing or fuselage panel. An airplane damaged in service by accident or serious incident is repaired by removing the damaged area and by bonding or fastening a patch. The total cost of repair is expected to decrease by the combination of the time-limited and permanent repair. Thus, it is important to grasp the strength characteristics on a small patch for the time-limited repair and a large patch for the permanent repair. In this paper a fuselage panel made of thin CFRP laminates and a specimen repaired by bonding a CFRP patch to the panel with a rectangular hole were tensile tested. The broken specimens were observed precisely in detail by both a magnifying glass and an optical microscope, which leads to the result that different sizes of patch have different initial failure points. That is, time-limited and permanent patches have the cohesive failure at central and side patch ends, respectively.
