Pre-Cured Composite Strip for Caul Plate Seam Inconsistencies
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Composite components, particularly in aircraft, often exhibit inconsistencies such as visible marks and fiber distortion at caul plate seams due to thermal expansion and movement during the curing process, which affect the surface aesthetics and require excessive sanding or filler application to hide these imperfections.
Innovation Solution
A pre-cured composite strip with thermoset resin is applied to areas where caul plate seams are expected, providing stiffness to prevent caul plate movement and fiber distortion, thereby minimizing inconsistencies and improving surface appearance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple caul plates are used during curing, then the outer mold line control and surface smoothness are improved, but visible seams and fiber distortion occur at the edges of adjacent caul plates
Solution Approach 1:
A pre-cured composite strip is applied to the outer surface of the composite component at locations where caul plate seams are expected to occur before the final curing process. This preliminary action creates a protective layer that prevents fiber distortion and visible seams at the caul plate edges during the curing process.
Solution Approach 2:
The pre-cured composite strip acts as an intermediary layer between the caul plate edges and the composite component surface. This intermediary strip absorbs the thermal expansion and movement effects, preventing direct contact between the caul plate edges and the composite fibers, thereby eliminating visible seams and fiber distortion.
2Stability of the object's composition
If caul plates are placed with gaps to accommodate thermal expansion, then thermal expansion is accommodated, but inconsistencies such as visible marks and fiber waviness occur at the plate edges
Solution Approach 1:
The pre-cured composite strip is applied in advance at the expected caul plate seam locations, creating a protective barrier before the thermal expansion and gap formation occur during curing. This preliminary placement ensures that even when gaps form for thermal expansion, the pre-applied strip prevents fiber distortion and visible marks at the plate edges.
3Object-generated harmful factors
If fillers and surfacing methods are used to reduce visibility of inconsistencies, then surface appearance is improved, but the process complexity and time increase
Solution Approach 1:
By applying the pre-cured composite strip before curing, the invention prevents inconsistencies at their source rather than requiring subsequent corrective measures like fillers and extensive surfacing. This preliminary preventive action eliminates the need for complex post-processing steps, reducing both process complexity and time while achieving the same surface appearance improvement.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The use of a pre-cured composite strip reduces the visibility of caul plate seams, minimizes fiber waviness, and allows for larger gap tolerances between caul plates, resulting in a smoother, more aesthetically pleasing surface finish with reduced need for filling and sanding.
Implementation Method 1
A pre-cured composite strip having a thermoset resin may be placed on a surface of a portion of the composite component
Implementation Method 2
A gap may be left between adjacent caul plates to accommodate caul plate thermal expansion of the curing and/or heating processes during composite component fabrication
Data Source
Figure 1~2
Figure 3A~3D
Figure 4~5
AI summary
A method and apparatus for applying a pre-cured composite strip to a composite component. A pre-cured composite strip having a thermoset resin may be placed on a surface of a portion of the composite component where a caul plate seam may be expected. Caul plates may be placed on the composite component after placing the pre-cured composite strip to form the caul plate seam. The composite component may be cured after placing the caul plates on the composite component.