Methods for repairing composite material using pre-cured plugs

A method for repairing a honeycomb panel comprising a low-density core sandwiched between two facesheets made of laminated plies of composite material, wherein portions of the two facesheets form an edge band comprising a first composite laminate having an outer boundary formed by edges of the laminated plies of the two facesheets, which outer boundary extends from the outer mold line surface to the inner mold line surface of the first composite laminate, the method comprising:

• (a) removing composite material from the first composite laminate, including a portion of the outer boundary, to form a double-tapered slot bounded by a first tapered internal surface that extends from an opening at an outer mold line surface of the first composite laminate and a second tapered internal surface that extends from an opening at an inner mold line surface of the first composite laminate to an intersection with the first tapered internal surface;
• (b) machining a second composite laminate to form a first plug having a tapered surface;
• (c) placing the first plug in the double-tapered slot so that the tapered surface of the first plug opposes the first tapered internal surface of the first composite laminate;
• and
• (d) machining a third composite laminate to form a second plug having a tapered surface;
• (e) placing the second plug in the double-tapered slot so that the tapered surface of the second plug opposes the second tapered internal surface of the first composite laminate;
• and
• (f) bonding the tapered surface of the first plug to the first tapered internal surface of the first composite laminate and bonding the tapered surface of the second plug to the second tapered internal surface of the first composite laminate,
• wherein subsequent to removing composite material and prior to placing the first and second plugs in the double-tapered slot, the double-tapered slot extends to the outer boundary of the first composite laminate to form a gap in the outer boundary where portions of the edges of the laminated plies in the edge band were removed.

A method for repairing a honeycomb panel comprising a low-density core sandwiched between two facesheets made of laminated plies of composite material, wherein portions of the two facesheets form an edge band comprising a first composite laminate having an outer boundary formed by edges of the laminated plies of the two facesheets, which outer boundary extends from an outer mold line surface to an inner mold line surface of the first composite laminate, the method comprising:

• (a) removing composite material from the first composite laminate, including a portion of the outer boundary, to form a tapered slot bounded by a tapered internal surface that extends from a first opening at the outer mold line surface of the first composite laminate to a second opening at the inner mold line surface of the first composite laminate;
• (b) machining a second composite laminate to form a plug having a tapered surface designed to oppose the tapered internal surface of the first composite laminate when the plug is placed in the tapered slot;
• (c) placing the plug in the tapered slot so that the tapered surface of the plug opposes the first tapered internal surface of the first composite laminate;
• and
• (d) bonding the tapered surface of the plug to the tapered internal surface of the first composite laminate,
• wherein subsequent to removing composite material and prior to placing the plug in the tapered slot, the tapered slot extends to the outer boundary of the first composite laminate to form a gap in the outer boundary where portions of the edges of the laminated plies in the edge band were removed.