Crash-Load Absorbing Tank Fitting With Breakaway Energy Dissipation

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Solution Overview

Problem

Existing technologies lack an effective solution for protecting hydrogen tanks in aircraft or spacecraft from significant damage during crash scenarios, such as crash landings, while also minimizing damage to other components.

Innovation Solution

A crash-load absorbing attachment fitting is proposed, comprising a joint that breaks at a pre-determined load-absorption activation threshold, activating a destroyer device to destructively act on the attachment fitting parts, effectively absorbing crash loads and protecting the hydrogen tank.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a rigid attachment fitting is used to securely mount a hydrogen tank, then the tank is well protected during normal operation, but the tank and components suffer significant damage during crash scenarios

Engineering Contradiction:
Improvetank protection during normal operationVSAvoidcrash damage to tank and components
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The attachment fitting is divided into multiple load-bearing parts connected by joints that can break at predetermined thresholds. This segmentation allows the structure to progressively fail in controlled ways, separating the protective function during normal operation from the crash load management function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Destroyer devices are pre-installed on the load-bearing parts, positioned to actively destroy remaining structural elements when joints break during a crash. This beforehand preparation ensures that crash loads are actively managed to protect the tank, rather than relying on passive structural integrity alone.

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

2Reliability

If heavier protective structures are added to protect the hydrogen tank during crashes, then tank integrity is improved, but the overall weight of the aircraft or spacecraft increases

Engineering Contradiction:
Improvetank integrity during crashesVSAvoidaircraft or spacecraft weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The load-bearing parts are made from fibre-reinforced composite materials, which provide high strength-to-weight ratio. This allows the attachment fitting to offer adequate crash protection while minimizing the added weight compared to traditional metallic protective structures.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The joint breaking load-absorption activation threshold is carefully designed and tuned to match expected crash scenarios. This parameter optimization ensures that the protective structure activates at the right moment without requiring excessive structural mass, balancing protection effectiveness with weight constraints.

Inventive Principle:
Principle #35Parameter changes

3Strength

If stronger attachment fittings are used to secure the hydrogen tank, then normal operation safety is improved, but crash loads are not effectively absorbed

Engineering Contradiction:
Improveattachment fitting strength during normal useVSAvoidcrash load absorption capability
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The attachment fitting transitions from a static strong structure to a dynamic system with predetermined failure points. The joints are designed to break at specific load thresholds, transforming the structure from rigid to progressively collapsible during crashes, enabling effective energy absorption through controlled deformation and destruction.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The destroyer devices are designed to actively destroy parts of the attachment fitting during crashes, converting the harmful crash energy into beneficial controlled destruction. This deliberate destruction of non-critical components absorbs crash loads that would otherwise be transmitted to the hydrogen tank, turning a negative outcome into a protective mechanism.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 effectively limits loads on the hydrogen tank and other components during crashes, ensuring the tank's integrity and preventing damage, while also enabling weight and cost reductions through the use of fibre-reinforced composite materials.

Implementation Method 1

the joint is configured such that the joint breaks when the load reaches or exceeds the pre-determined load-absorption activation threshold value

Methodology Applied
Scientific EffectFracture Mechanics: Fracture Mechanics

Implementation Method 2

the destroyer device is arranged so as to be capable of destructively acting on the other one of the first and second parts after breaking of the joint

Methodology Applied
Scientific EffectKinetic Energy Absorption through Fracture: Fracture Mechanics

Implementation Method 3

both the first and second parts are each made with a fibre-reinforced composite material... capable of consuming considerable amounts of kinetic energy during destruction thereof

Methodology Applied
Scientific EffectEnergy Absorption through Material Destruction: Fracture Mechanics

Data Source

PatentEP4556373A1Crash-load absorbing attachment fitting and aircraft or spacecraft comprising the same
Publication Date: 2025.05.21 AIRBUS OPERATIONS GMBH
  • EP4556373A1 patent drawingFigure 1~2
  • EP4556373A1 patent drawingFigure 3

AI summary

The present invention relates to a crash-load absorbing attachment fitting (1; 101; 201; 301; 401), comprising a first and second part (3, 6; 103, 106; 203, 206; 303, 306; 403, 406) that are joined to each other at a joint (10; 110; 210; 310; 410), the first and second parts being load-bearing parts. The joint is configured such that the joint is capable of transferring, during normal use of the crash-load absorbing attachment fitting, a load (F) which is below a pre-determined load-absorption activation threshold value between the first and second parts, and such that the joint breaks when the load reaches or exceeds the pre-determined load-absorption activation threshold value. The crash-load absorbing attachment fitting further comprises a destroyer device (15; 115; 215; 315; 415), wherein the destroyer device is rigidly connected to and/or rigidly supported by one of the first and second parts and wherein the destroyer device is arranged so as to be capable of destructively acting on the other one of the first and second parts after breaking of the joint. Moreover, the invention proposes an aircraft or spacecraft (91) comprising a tank for storing hydrogen, in particular liquefied hydrogen, and at least one such crash-load absorbing attachment fitting (1; 101; 201; 301; 401), the tank being attached to a structural member (78) of the aircraft or spacecraft using the crash-load absorbing attachment fitting.