Composite Aircraft Door Fuselage Structure Adhesive Bonding
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Solution Overview
Problem
Aircraft doors made of composite materials face challenges with high manufacturing costs and maintenance issues due to the use of rivets, which are both expensive and heavy, while requiring reliable pressure resistance and emergency opening capabilities.
Innovation Solution
A fuselage structure using composite materials with form locking engagement between panels and inner structural elements, supplemented by adhesive bonding, eliminates the need for rivets and incorporates Resin Transfer Molding for optimized low weight and production costs, employing fiber-reinforced plastics and additional adhesive layers for enhanced bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rivets are used to mount composite panels to beam elements, then the structural connection and load distribution are achieved, but the manufacturing cost increases and maintenance issues arise
Solution Approach 1:
The patent replaces the mechanical fastening system (rivets) with a chemical bonding system (adhesive). The adhesive bonding process eliminates the need for drilling holes and inserting rivets, thereby reducing manufacturing complexity and cost while maintaining structural integrity. The adhesive layer creates a continuous bond between the composite panel and beam elements, distributing loads effectively without the discontinuities introduced by rivet holes.
Solution Approach 2:
The patent employs composite materials in the adhesive layer and bonding structures to achieve both structural strength and cost-effectiveness. The use of fiber-reinforced adhesive compositions allows the bonding system to meet the rigorous pressure resistance requirements while being more economical than metal rivet systems, particularly for large-area bonding applications in aircraft doors.
2Reliability
If rivets are used to mount composite panels to beam elements, then the structural connection and load distribution are achieved, but maintenance issues increase
Solution Approach 1:
By replacing the mechanical rivet system with an adhesive bonding system, the patent eliminates maintenance issues associated with rivet corrosion, loosening, and fatigue. Adhesive bonds provide a more uniform stress distribution and are less susceptible to environmental degradation, thereby reducing maintenance requirements and improving long-term reliability of the aircraft door structure.
3Strength
If traditional mounting methods are used, then structural integrity is achieved, but weight increases due to rivets
Solution Approach 1:
The patent replaces heavy metal rivets with a lighter adhesive bonding system. The adhesive layer, typically only millimeters thick, provides sufficient bonding strength while significantly reducing the overall weight of the door assembly compared to a rivet system that requires holes, rivet shanks, and additional fastening hardware.
4Ease of manufacture
If adhesive bonding alone is used to mount panels to beams, then manufacturing simplicity is improved, but load transfer capability may be insufficient
Solution Approach 1:
The patent employs composite adhesive materials, particularly fiber-reinforced adhesives, to enhance the load transfer capability of the bonding system. These composite adhesives provide both the chemical bonding benefits of adhesives and the mechanical strength of fiber reinforcement, enabling the system to handle the high loads and pressure differentials experienced by aircraft doors while maintaining manufacturing simplicity.
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 solution provides highly reliable, lightweight aircraft doors with reduced production costs and maintenance burdens, effectively transferring loads from internal pressure through form locking and adhesive mounting, enhancing structural integrity and stability.
Implementation Method 1
at least one group of layers of composite material of the panel is in form locking engagement with this flange of the beam
Implementation Method 2
At least one group of layers of composite material of the panel is in form locking engagement with this flange of the beam
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The present invention relates to a fuselage structure, particularly an aircraft door (1) of composite material comprising at least one panel (2) and at least one beam (3) mounted to each other, with the panel (2) being formed of at least one group of composite layers (5,6,20). The at least one beam (3) is provided at least at one of its respective ends (10,11) with a flange (13) suitable for adhesive engagement with the at least one panel (2). The at least one group of composite layers (5,6,20) of the panel (2) is in form locking engagement with this flange (13) of the beam (3).