Composite Truss Panel With Fluted Core And Foam Stiffeners
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing composite materials for cryogenic fuel tanks face challenges such as weight, structural integrity, and permeability issues under severe environmental conditions, particularly in aerospace applications, where they need to withstand cryogenic temperatures and rapid temperature changes.
Innovation Solution
A sandwich-in-sandwich composite truss panel with a fluted core and integral lightweight foam stiffeners, using high-temperature low-density foam for structural support and thermal insulation, which allows for thinner designs and improved structural properties, including buckling and impact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a laminated fluted sandwich design is used, then the structural design is achieved, but thick walls are required to carry compression and shear loads
Solution Approach 1:
The patent employs a composite sandwich structure combining fluted core walls with foam material and facesheets. This composite approach allows the structure to achieve required compression and shear strength while using thinner walls compared to conventional laminated fluted designs, thereby reducing overall weight.
Solution Approach 2:
The patent introduces foam material specifically within the fluted core structure at locations where strength is needed, rather than uniformly thickening all walls. This localized reinforcement provides the necessary compression and shear capacity while minimizing overall weight increase.
2Strength
If honeycomb design is used, then the core structure is achieved, but the weight is relatively heavy and flatwise tensile strength and shear strength are reduced
Solution Approach 1:
The patent uses a fluted core design that segments the core into multiple hollow flutes rather than using a solid honeycomb structure. This segmentation provides structural strength while reducing weight, and the flutes are arranged to optimize both tensile and shear performance in the flatwise direction.
Solution Approach 2:
The patent combines the fluted core structure with foam material and composite facesheets to achieve the required flatwise tensile and shear strength. This composite approach allows the structure to meet strength requirements without the excessive weight of conventional honeycomb designs.
3Object-affected harmful factors
If core cell walls are perforated to purge volatile fuels, then pressure build-up is reduced, but shear, compression and bending strength are reduced
Solution Approach 1:
The patent extracts the volatile fuel purge function from the core cell walls by providing dedicated purge paths through the fluted core structure without requiring perforations in the load-bearing walls. This separation allows the walls to maintain full strength while still enabling vapor removal.
Solution Approach 2:
The patent introduces foam material as an intermediary within the fluted core that facilitates vapor transport and pressure equalization without requiring perforations in the structural walls. The foam provides pathways for volatile fuel removal while the solid wall sections maintain their full shear, compression, and bending strength.
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 a lightweight, high-strength structure capable of withstanding cryogenic temperatures and rapid temperature changes, reducing weight and cost while maintaining structural performance, and enabling efficient vapor purging and thermal isolation.
Implementation Method 1
The use of low density foam in the outer and/or flute walls may permits the various layers of the panel to be thermally isolated
Implementation Method 2
The hollow geometry of the fluted core allows any fuel vapors trapped in the core to be readily purged
Data Source
AI summary
A composite truss structure employs a sandwich-in-sandwich construction in which a composite fluted core is sandwiched between two facesheets, and at least one structural foam stiffener is sandwiched within the core or between the facesheets and/or the core.