Fuselage Tank Lattice Support for Cryogenic Impact Energy Absorption

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Solution Overview

Problem

Aircrafts using cryogenic fuels face challenges in accommodating large fuel tanks due to insufficient volume in conventional wing structures, requiring oversized fuselages and needing robust support to withstand static, dynamic, and impact loads while maintaining fuel integrity.

Innovation Solution

A fuselage assembly with a lattice structure support unit is integrated into the fuselage to provide elastic and plastic deformations, mimicking the Pomelo fruit's cellular composition, absorbing impact energy and distributing loads effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If large fuel tanks are installed to accommodate cryogenic fuels, then fuel capacity is improved, but fuselage size and structural complexity increase

Engineering Contradiction:
Improvefuel capacityVSAvoidfuselage volume
Core Design Contradiction:
Quantity of substanceVSVolume of stationary object

Solution Approach 1:

The patent employs a foam-like cellular support structure within the fuselage that provides both structural support and energy absorption capabilities. This porous cellular material allows the fuselage to accommodate large fuel tanks while maintaining a compact overall size, as the cellular structure efficiently utilizes space and provides multifunctional performance.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The fuselage assembly combines different materials including the foam-like cellular support structure, tank walls, and insulation layers to create a composite system. This composite approach allows optimization of each component for its specific function while achieving overall system efficiency in terms of space utilization and structural performance.

Inventive Principle:
Principle #40Composite materials

2Reliability

If thick tank walls are used to prevent leakage under crash scenarios, then reliability is improved, but weight increases

Engineering Contradiction:
Improvetank integrity under impactVSAvoidtank weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent incorporates a foam-like cellular support structure that acts as a cushioning element between the fuel tank and the fuselage structure. This support structure is designed to deform and absorb impact energy during crash scenarios, protecting the tank from direct impact forces. This beforehand cushioning allows the use of thinner tank walls while maintaining reliability under impact conditions.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The foam-like cellular structure serves as an intermediary element between the fuel tank and the external environment (including impact forces). This mediator absorbs and dissipates energy, reducing the direct transmission of impact forces to the tank walls, thereby allowing thinner walls while maintaining integrity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Temperature

If double wall structure with insulation is implemented to maintain cryogenic temperatures, then temperature control is improved, but device complexity increases

Engineering Contradiction:
Improvecryogenic temperature maintenanceVSAvoidtank structure complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent merges multiple functions into the foam-like cellular support structure. This single component simultaneously provides structural support for the tank, thermal insulation to maintain cryogenic temperatures, and impact energy absorption. By combining these functions into one integrated element rather than separate components, the overall device complexity is reduced while achieving the required temperature control.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The foam-like cellular structure is designed as a multi-functional element that performs support, insulation, and energy absorption functions. This universal component approach simplifies the overall tank structure by eliminating the need for separate support structures, insulation layers, and crashworthiness elements, thereby reducing device complexity while maintaining temperature control.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Strength

If foam-like cellular support structure is used to absorb impact energy, then crashworthiness is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveimpact energy absorptionVSAvoidsupport structure fabrication
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent utilizes additive manufacturing technology to create the foam-like cellular support structure with specific geometric parameters optimized for energy absorption. By controlling parameters such as cell size, wall thickness, and density during the additive manufacturing process, the structure achieves high impact energy absorption capabilities. This manufacturing approach, while advanced, allows for precise control of structural properties and can be more efficient than traditional manufacturing methods for complex cellular geometries.

Inventive Principle:
Principle #35Parameter changes

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 lattice structure enhances the fuselage's ability to absorb impact energy and distribute loads, improving structural behavior during crashes and maintaining fuel integrity by minimizing coupling forces on the tank.

Implementation Method 1

A fundamental concept of the invention is to provide a fuselage assembly that carries static and/or dynamic loads (such as flight, ground and thermal loads during normal operation) by providing an elastic deformation

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

provide a fuselage assembly that carries static and/or dynamic loads (such as flight, ground and thermal loads during normal operation) by providing an elastic deformation in such cases as well as impact loads by providing a plastic deformation

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP4656525A1Fuselage assembly for tank integration and absorbing impact energy, and aircraft
Publication Date: 2025.12.03 AIRBUS OPERATIONS GMBH
  • EP4656525A1 patent drawingFigure 1~2
  • EP4656525A1 patent drawingFigure 3~4
  • EP4656525A1 patent drawingFigure 5

AI summary

The present invention provides a fuselage assembly (1) for tank integration and absorbing impact energy, in particular being used in an aircraft, the fuselage assembly (1) comprising: a tank device (2); a fuselage structure (3) with a fuselage diameter (d3), wherein the fuselage structure (3) at least partly encloses the tank device (2); and a support unit (4) with a lattice structure for supporting the tank device (2) inside the fuselage structure (3), wherein the support unit (4) is at least sectionwise in contact with the tank device (2) and the fuselage structure (3), wherein the lattice structure has a first characteristic length (l1) that is about one fiftieth of the fuselage diameter (d3) or less. Further the present invention provides an aircraft (10) comprising such a fuselage assembly (1).