Repair Patch Removal Layer Slits Prevent Fiber Meandering
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Solution Overview
Problem
Existing methods for repairing composite materials often result in fiber meandering, which hinders the recovery of the part's strength, as the fiber reinforced preforms fail to maintain an appropriate shape during the repair process.
Innovation Solution
A repair patch with a laminate structure and a removal layer that includes slits or through-holes, allowing the removal layer to press and shape the fiber reinforced preforms, preventing fiber meandering and enhancing bondability by peeling off to expose the bonding surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If fiber reinforced preforms are laminated to form a repair patch, then the repair patch can be created to repair composite material, but fiber meandering occurs in the end portions of the preforms, reducing the strength recovery
Solution Approach 1:
A removal layer is provided on the bonding surface of the repair patch before bonding occurs. This removal layer includes processed portions (such as slits or recesses) that are formed in advance at positions facing the end portions of the fiber reinforced preforms. During the bonding process, these processed portions press the end portions of the preforms, preventing fiber meandering and ensuring proper shaping before the patch is applied to the damaged area.
2Shape
If the repair patch is molded with an inclined surface bonding area, then better bonding geometry is achieved, but fiber meandering occurs at the inclined surface end portions
Solution Approach 1:
The removal layer acts as an intermediary element between the inclined surface of the repair patch and the fiber reinforced preforms. The processed portions of the removal layer (slits or recesses) physically press and constrain the end portions of the preforms during bonding, preventing fiber meandering while allowing the inclined surface geometry to be maintained for optimal bonding contact.
3Ease of manufacture
If conventional repair methods are used without a removal layer, then the process is simpler, but fiber meandering occurs and strength recovery is insufficient
Solution Approach 1:
The removal layer with its processed portions is incorporated into the repair patch manufacturing process in advance. This preliminary structure is designed to automatically press and shape the fiber reinforced preforms during bonding, preventing fiber meandering without requiring complex additional steps or equipment during the actual repair operation.
Data Source
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AI summary
Provided is a repair patch 10 for a composite material to repair a part 5 to be repaired which is a repair target of the composite material, the patch including: a patch main body 11 that is formed by laminating a plurality of prepregs P in a thickness direction, and has a bonding surface 18 to be bonded to the part 5 to be repaired; and a removal layer 12 that is provided on the bonding surface 18 and is peelable off from the patch main body 11. The bonding surface 18 includes a side surface 13 that is inclined with respect to the thickness direction of the patch main body 11. The removal layer 12 includes a plurality of slits 17 that cause the removal layer 12 to have a shape complementary to a shape of the side surface 13 of the patch main body 11.