Bonded Structures Using Partially Cured Adhesive Films
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for validating the strength of bonded structures in aircraft are limited, as applying a load to test bond strength can damage the structure and fail to detect contamination issues like 'kissing bonds, and secondary bonded joints with fully cured components are difficult to certify, leading to reliance on expensive and heavy fastened joints.
Innovation Solution
A method involving the use of partially or fully uncured adhesive films, cured separately and then assembled under pressure in a clean room environment, with a distinct cure cycle to form a bonded structure, allowing for certifiable joints without fasteners and surface preparation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a load is applied to test bond strength, then bond strength validation is achieved, but the bonded structure can be damaged
Solution Approach 1:
The adhesive film is applied and cured to form a bonded structure before the aircraft component is subjected to service loads. This preliminary bonding action allows the bond to be validated through subsequent non-destructive inspection methods rather than destructive load testing, thereby avoiding damage to the bonded structure while still achieving reliability validation
Solution Approach 2:
The invention uses a test coupon or test specimen that replicates the bonding conditions and adhesive formulation of the actual bonded structure. By testing the coupon instead of the actual structure, bond strength validation is achieved without compromising the integrity of the operational bonded component
2Strength
If fully cured components are used for secondary bonding, then component strength is ensured, but bonding difficulty increases due to surface contamination and certification challenges
Solution Approach 1:
A bonding surface is prepared on the fully cured component by applying the adhesive film before final assembly. This preliminary preparation ensures that the bonding surface is clean and ready for bonding, eliminating contamination issues that would arise from storing pre-cured components and later preparing surfaces for bonding
Solution Approach 2:
The adhesive film serves as an intermediary layer between the fully cured component and the mating component. This intermediary allows bonding to occur on fully cured components without requiring surface preparation, as the adhesive film creates a fresh bonding interface that eliminates contamination problems
3Reliability
If fastened joints are used instead of bonded structures, then certification is easier, but weight and cost increase
Solution Approach 1:
A test coupon replicating the bonding conditions is used to validate the bonded joint for certification purposes. This allows certification to proceed without requiring the actual bonded structure to be tested destructively, enabling bonded structures to be certified with the same ease as traditional fastened joints while maintaining the weight advantages of bonding
Solution Approach 2:
The adhesive film is applied and cured to form the bonded joint before final assembly and certification testing. This preliminary bonding allows non-destructive validation methods to be used for certification, eliminating the need for heavy fasteners while maintaining certification ease
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
This approach enables the formation of certifiable bonded structures that are lighter, cheaper, and more aerodynamic, eliminating the need for fasteners and reducing the risk of contamination, while ensuring validated bond strengths.
Implementation Method 1
curing the first adhesive film and the second adhesive film to form a bonded structure
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3
AI summary
A method is provided in one example embodiment and may include assembling a first component (408) and a second component (458) together using, at least in part, a first adhesive film (404) on the first component (408) and a second adhesive film (454) on the second component (458), wherein the first component (408) and the second component (458) are fully cured and the first adhesive film (404) and the second adhesive film (454) are at least partially uncured; and curing the first adhesive film (404) and the second adhesive film (454) to form a bonded structure (490).