Composite Panel Non-Planar Core Crushing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing composite panels with uniform honeycomb cores are inadequate for non-planar surfaces, as they fail to provide sufficient structural integrity and anchorage for equipment mounting, especially in non-flat applications like door and floor panels in aircraft.
Innovation Solution
A composite panel design featuring non-planar skin laminae with recessed areas, a polymer honeycomb core of non-uniform thickness, and local reinforcements, such as stacked laminae or thermoset mouldings, bonded using elevated temperature and pressure, with adhesives like non-woven polyester scrims, to enhance structural support and anchorage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a uniform honeycomb core is used in composite panels, then the manufacturing process is simple, but the panel cannot provide sufficient structural integrity and anchorage for non-planar surfaces
Solution Approach 1:
The patent applies local quality by varying the honeycomb core thickness to match the non-planar requirements of different panel regions. Thinner core sections are used in recessed areas while thicker sections provide structural support in elevated areas, allowing each region to have the appropriate structural properties for its specific function.
Solution Approach 2:
The honeycomb core is segmented into multiple thickness zones to accommodate the non-planar surface requirements. This segmentation allows the panel to be divided into functional regions with different structural characteristics, enabling both structural integrity and proper anchorage for equipment mounting.
2Shape
If the honeycomb core is crushed to match recessed areas, then the non-planar surface shape is achieved, but the core thickness becomes non-uniform requiring complex manufacturing
Solution Approach 1:
The skin laminae are pre-formed with the desired non-planar shape and recessed areas before assembly. This preliminary shaping allows the core to be crushed and conform to the predetermined surface geometry, simplifying the manufacturing process by establishing the final shape early in the fabrication sequence.
Solution Approach 2:
The core thickness parameter is deliberately changed from uniform to non-uniform through controlled crushing. This parameter change allows the core to adapt to the non-planar surface requirements while maintaining manufacturability through the use of thermoplastic materials that can be heated and formed.
3Reliability
If local reinforcements are added to enhance anchorage, then the equipment mounting capability is improved, but the panel structure becomes more complex
Solution Approach 1:
Local reinforcements are merged with the skin laminae through bonding, creating an integrated structure. The reinforcements are combined with the existing panel architecture rather than being added as separate components, which enhances anchorage capability while minimizing the increase in overall structural complexity.
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 enhanced structural integrity and secure anchorage for equipment, enabling the use of composite panels in non-planar applications like aircraft door and floor panels, with improved bonding and reinforcement methods that maintain core adhesion and support.
Implementation Method 1
compressing the assembly at elevated temperature to crush the core to a lesser thickness at the recessed area(s) of the non-planar skin laminae
Implementation Method 2
compressing the assembly at elevated temperature to crush the core
Implementation Method 3
an adhesive material is employed between the laminae and the reinforcement
Implementation Method 4
compression at elevated temperature, in like manner to bonding of the laminae to the core
Data Source
AI summary
A door panel 1 has a peripheral frame 10 of extruded aluminum and a honeycomb core of plastics material tubes 11. An outer skin 2 of fiber-reinforced polyetherimide material is recessed with a pattern 3 formed in a preliminary operation of vacuum/pressure forming at elevated temperature. An inner skin 4 is plane. Edge channel members 5 of similarly formed, but thicker material are arranged around the edges of the door, enclosing the aluminum frame. A non-woven, polyester based scrim 6 extends across either side of the core and over the flanges 7 of the edge channels.For bonding of the core, skin and edge channels together, the assembly is placed in a jig and compressed at elevated temperature in a heated press. The core is crushed at the recessed pattern 3 and the scrim melts and acts as a hot melt adhesive. On cooling of the press platens, the assembled door is removed from the jig.