Aircraft Shell Pre-Buckling Design for Composite Stability

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Solution Overview

Problem

Current aircraft surface components made of fiber composite materials fail to utilize the post-buckling area effectively, leading to sudden material failure under overload, which reduces their load-bearing capacity and stability compared to metallic structures.

Innovation Solution

The surface component is designed with a pre-buckling structure, either through intentional imperfections or asymmetrical fiber composite construction, to deliberately buckle in a predetermined direction under load, allowing it to utilize the post-buckling area and increase bearable loads while reducing mass.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If fiber composite materials are used for shells and stiffening structures, then weight is reduced, but sudden material failure occurs under overload due to inability to utilize post-buckling area

Engineering Contradiction:
Improveweight of surface componentVSAvoidload-bearing capacity under overload
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-forming the shell with intentional geometric imperfections or asymmetrical fiber composite construction during manufacturing. These pre-buckling structures are created before the component is subjected to loads, enabling the shell to buckle in a predetermined direction when overloaded, thereby preventing sudden catastrophic failure and allowing utilization of the post-buckling load-bearing area.

Inventive Principle:
Principle #10Preliminary action

2Duration of action of stationary object

If metallic structures are designed for stability below limit load, then fatigue resistance is improved, but post-buckling area cannot be utilized

Engineering Contradiction:
Improvefatigue resistanceVSAvoidload-bearing capacity in post-buckling area
Core Design Contradiction:
Duration of action of stationary objectVSStrength

Solution Approach 1:

The patent applies asymmetry by creating asymmetrical fiber composite construction or intentional geometric imperfections in the shell. This asymmetrical design causes the shell to buckle in a predetermined direction under overload, enabling the structure to utilize the post-buckling area for load-bearing, thereby increasing strength while maintaining fatigue resistance through proper design below limit loads.

Inventive Principle:
Principle #4Asymmetry

3Weight of stationary object

If fiber composite materials are used, then mass is reduced, but sudden deformation and material failure occur under overload

Engineering Contradiction:
Improvemass of surface componentVSAvoidstability under overload
Core Design Contradiction:
Weight of stationary objectVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by pre-forming the shell with intentional geometric imperfections or asymmetrical fiber composite construction during manufacturing. These pre-buckling structures are created before the component is subjected to loads, enabling the shell to buckle in a predetermined direction when overloaded, thereby preventing sudden catastrophic failure and allowing utilization of the post-buckling load-bearing area.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies parameter changes by modifying the geometric parameters of the shell through intentional imperfections or asymmetrical material distribution. These parameter changes alter the buckling behavior of the shell, causing it to buckle in a predetermined direction under overload, thereby improving stability while maintaining the mass benefits of fiber composite materials.

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

This design enables the surface component to withstand higher loads with the same load capacity and reduced mass, maintaining stability and load-bearing capacity similar to perfect structures, while minimizing sudden deformation and fatigue effects.

Implementation Method 1

a pre-buckling structure which causes the shell to buckle in a predetermined direction under a load acting on the shell in a direction parallel to the shell

Methodology Applied
Scientific EffectBuckling: Deformation

Data Source

PatentEP2730496B1Panel for aircraftand method of producing the same
Publication Date: 2019.06.12 AIRBUS DEFENCE & SPACE GMBH
  • EP2730496B1 patent drawingFigure 1
  • EP2730496B1 patent drawingFigure 2~4
  • EP2730496B1 patent drawingFigure 5

AI summary

The component (16) has a shell (20) comprising a pre-forming structure, which makes pre-forming of the shell under load in a pre-determined direction, where the load acts in a direction parallel to the shell. The shell is made of a fiber composite material. The fiber composite material is asymmetrically constructed with respect to a center surface of the shell to cause pre-forming under load. The shell comprises an arrangement of deflection fields, and is deflected in transverse direction. A reinforcing grid structure (22) is arranged on a side of the shell. An independent claim is also included for a method for manufacturing a surface component for an aircraft.