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US 5,882,756 AGranted
Composite patches having Z-pin reinforcement
AssigneeThe Boeing Company
InventorsMark S. Alston, Joseph P. Brown, James J. Childress
Life of this patent
Estimating the term…
Abstract
The strength of composite patches is improved over conventional bolted or bonded patches by including Z-pins in the patch/parent structure interface to provide a mechanical link with small stress concentration between the patch and the parent structure. In some cases, we achieve a stronger repair removing the pins to leave holes that fill with resin from the patch during the curing or bonding operation.
Claims20
A patched laminated composite structure, made by the method comprising the steps of:
- (a) scarfing an outer exposed surface of the composite structure to expose a patch interface through at least one ply of the composite structure;
- (b) applying patch material along the interface to form a patch to restore the composite structure, the patch being flush with the outer exposed surface of the composite;
- (c) applying an adhesive between the patch material and composite structure on at least a portion of the interface;
- (d) inserting Z-pins with an ultrasonic horn along at least a portion of the interface between the patch material and the composite structure sufficient to hold the patch firmly in place;
- (e) optionally, removing at least a portion of the Z-pins to leave spaced holes between the patch material and composite structure;
- and
- (f) bonding the patch material to the composite structure by heating the adhesive.
4 more elements
A patched laminated composite structure, made by the method comprising the steps of:
- (a) scarfing the composite structure to expose a patch interface through at least one ply of the composite structure;
- (b) applying patch material along the interface to restore the composite structure;
- (c) optionally, applying an adhesive between the patch material and composite structure on at least a portion of the interface;
- (d) inserting Z-pins along at least a portion of the interface between the patch material and the composite structure;
- (e) optionally, removing at least a portion of the Z-pins to leave spaced holes between the patch material and composite structure;
- and
- (f) bonding the patch material to the composite structure
- wherein the composite structure is a thermoplastic while the patch material is a thermoset.
5 more elements
A patched laminated composite structure, made by the method comprising the steps of:
- (a) scarfing the composite structure to expose a patch interface through at least one ply of the composite structure;
- (b) applying patch material along the interface to restore the composite structure;
- (c) optionally, applying an adhesive between the patch material and composite structure on at least a portion of the interface;
- (d) inserting Z-pins along at least a portion of the interface between the patch material and the composite structure;
- (e) optionally, removing at least a portion of the Z-pins to leave spaced holes between the patch material and composite structure;
- and
- (f) bonding the patch material to the composite structure
- wherein the patch material is applied in at least two portions and Z-pins are inserted separately in each portion.
5 more elements
A patched laminated composite structure, made by the method comprising the steps of:
- (a) scarfing the composite structure to expose a patch interface through at least one ply of the composite structure;
- (b) applying patch material along the interface to restore the composite structure;
- (c) optionally, applying an adhesive between the patch material and composite structure on at least a portion of the interface;
- (d) inserting Z-pins along at least a portion of the interface between the patch material and the composite structure;
- (e) optionally, removing at least a portion of the Z-pins to leave spaced holes between the patch material and composite structure;
- (f) bonding the patch material to the composite structure;
- and
- (g) applying at least one, pin-free surface ply over the pinned patch material.
5 more elements
A patched laminated composite structure, comprising:
- (a) a scarfed region in an outer, exposed surface of a laminated composite;
- (b) fiber-reinforced patch material abutting the laminated composite in the scarfed region to define an interface, the material extending flush with the surface;
- and
- (c) Z-pin reinforcement in selected locations at an areal density of about 0.375-1.50% in such locations between the composite and the patch material along at least a portion of the interface.
1 more element
A patched laminated composite structure, comprising:
- (a) a scarfed region in a laminated composite;
- (b) patch material abutting the laminated composite in the scarfed region to define an interface;
- and
- (c) Z-pin reinforcement further comprising at least one pin-free surface ply over the pinned patch material further compromising at least one pin-free surface ply over the pinned patch material.
1 more element
A patched laminated composite structure, comprising:
- (a) a scarfed region in a laminated composite;
- (b) patch material abutting the laminated composite in the scarfed region to define an interface;
- and
- (c) Z-pin reinforcement further comprising at least one pin-free surface ply over the pinned patch mate wherein the reinforcement is staggered along the interface with some pins inserted at a greater depth.
1 more element
A patched laminated composite structure having several plies comprising:
- (a) a scarfed region in a laminated composite;
- (b) patch material, having a resin, abutting the laminated composite in the scarfed region to define an interface;
- and
- (c) resin pillars between plies in the interface.
1 more element
Dependencies are inferred from the claim text.