A method for repairing a composite structure using pre-cured plugs. In accordance with one method, composite material is removed from a first composite laminate to form a cavity bounded by a tapered internal surface that extends from an opening at an outer mold line surface of the first composite laminate. In addition, a second composite laminate is machined to form a plug having a tapered surface. Then the plug is placed so that the tapered surface of the plug opposes the tapered internal surface of the first composite laminate. Thereafter, the tapered surface of the plug is bonded to the tapered internal surface of the first composite laminate. Optionally, a hole is drilled in the plug for receiving a fastener.

A method of debonding a first layer from a second layer, wherein the first layer is bonded to the second layer by an adhesive located between the first and second layers. The method includes inserting a blade of a cleaving tool between the first and second layers, and exerting a controlled force on the cleaving tool to move the cleaving tool so as to de-bond the first and second layers in a region. The force exerted is controlled to match a de-bonding force calculated for the region, and such that the movement of the cleaving tool stops when the calculated force is less than a force required to move the cleaving tool, and continues when the calculated force is higher than or equal to the force required to move the cleaving tool.

A method of debonding a first layer from a second layer, wherein the first layer is bonded to the second layer by an adhesive located between the first and second layers. The method includes inserting a blade of a cleaving tool between the first and second layers, and exerting a controlled force on the cleaving tool to move the cleaving tool so as to de-bond the first and second layers in a region. The force exerted is controlled to match a de-bonding force calculated for the region, and such that the movement of the cleaving tool stops when the calculated force is less than a force required to move the cleaving tool, and continues when the calculated force is higher than or equal to the force required to move the cleaving tool.

Complex laminated composites may be repaired by removal of individual damaged plies through peeling in order to exploit the weaker interlaminar properties of these composites. Upon removal of the individual damaged plies through peeling, replacement plies may be added to restore the laminated composite. In addition, when damage extends through the thickness of a laminated composite, a plug may be used to allow plies to be replaced while maintaining contour within the repair region. A caul plate also may be used to stiffen and maintain the contour of a repair region while peeling and removing plies from the repair region.

Complex laminated composites may be repaired by removal of individual damaged plies through peeling in order to exploit the weaker interlaminar properties of these composites. Upon removal of the individual damaged plies through peeling, replacement plies may be added to restore the laminated composite. In addition, when damage extends through the thickness of a laminated composite, a plug may be used to allow plies to be replaced while maintaining contour within the repair region. A caul plate also may be used to stiffen and maintain the contour of a repair region while peeling and removing plies from the repair region.

A method for recovering vinyl window frames. The method of recovering vinyl window frames includes identifying damages in an existing vinyl frame having a plurality of planes, wherein the damages exist in at least one plane, measuring the area of the frame to be covered, creating a template of the frame by securing pre-cut plates together with a gap between to allow for bending along the gap, such that the template can conform to the frame, marking cuts to be made to the replacement cover using the template, cutting the replacement cover to duplicate the existing frame, and applying the replacement cover over the existing vinyl frame.

A method for recovering vinyl window frames. The method of recovering vinyl window frames includes identifying damages in an existing vinyl frame having a plurality of planes, wherein the damages exist in at least one plane, measuring the area of the frame to be covered, creating a template of the frame by securing pre-cut plates together with a gap between to allow for bending along the gap, such that the template can conform to the frame, marking cuts to be made to the replacement cover using the template, cutting the replacement cover to duplicate the existing frame, and applying the replacement cover over the existing vinyl frame.

A repair and reinforcement method for an aircraft is provided. The method includes cleaning a corroded portion of a structure of the aircraft, applying an adhesive layer to the cleaned portion of the structure and forming a polymer matrix composite (PMC) patch for application to the adhesive.

A repair and reinforcement method for an aircraft is provided. The method includes cleaning a corroded portion of a structure of the aircraft, applying an adhesive layer to the cleaned portion of the structure and forming a polymer matrix composite (PMC) patch for application to the adhesive.

A method for repairing a damaged area of a stealth composite structure having a stealth function using a scarf patch includes the steps of diagnosing the damaged area; deriving a repair area including the diagnosed damaged area; processing the scarf patch according to the derived repair area; machining a patch hole according to the derived repair area to remove the damaged area; and coupling the scarf patch to the patch hole so that an inner wall of the patch hole and a side surface of the scarf patch face.