Aircraft Fuselage Pressure Bulkhead Stiffness

Solution Overview

Problem

Existing pressure bulkheads for aircraft fuselages face challenges in achieving high torsional and radial stiffness while minimizing weight, particularly when subjected to depressurization and flight loads, and require additional stiffeners which add complexity.

Innovation Solution

The use of special fastening means comprising a pair of annular attachment frames made of open or hollow profiles, forming a double box frame connection between the pressure bulkhead and the fuselage structure, which enhances torsional and radial stiffness through riveted connections, and can be made of metal or reinforced plastic materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If metal stiffeners are added to pressure bulkheads to support fuselage stress, then the stiffness is improved, but the weight increases and manufacturing complexity increases

Engineering Contradiction:

ImprovestiffnessVSAvoidweight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The patent changes the material parameter from traditional metal to composite materials (carbon fiber reinforced plastic), achieving high stiffness with reduced weight. The composite material provides equivalent or superior mechanical properties compared to metal stiffeners while significantly reducing the weight of the pressure bulkhead assembly.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials, specifically carbon fiber reinforced plastic, to construct the pressure bulkhead. This composite structure achieves the required stiffness and strength without needing additional metal stiffeners, thereby reducing overall weight and manufacturing complexity while maintaining structural integrity under fuselage stress.

Inventive Principle:

Principle #40Composite materials

2Strength

If metal stiffeners are added to pressure bulkheads to support fuselage stress, then the stiffness is improved, but the device complexity increases

Engineering Contradiction:

ImprovestiffnessVSAvoidcomplexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent changes the material parameter from traditional metal to composite materials (carbon fiber reinforced plastic), achieving high stiffness with reduced weight. The composite material provides equivalent or superior mechanical properties compared to metal stiffeners while significantly reducing the weight of the pressure bulkhead assembly.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials, specifically carbon fiber reinforced plastic, to construct the pressure bulkhead. This composite structure achieves the required stiffness and strength without needing additional metal stiffeners, thereby reducing overall weight and manufacturing complexity while maintaining structural integrity under fuselage stress.

Inventive Principle:

Principle #40Composite materials

3Strength

If additional stiffeners are used to maintain bulkhead stiffness, then the strength is improved, but the manufacturing effort increases

Engineering Contradiction:

ImprovestiffnessVSAvoidmanufacturing effort

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The patent segments the pressure bulkhead into a modular composite structure with distinct functional zones. The bulkhead is divided into areas with different fiber orientations and material compositions, allowing each segment to be manufactured independently and assembled together, reducing overall manufacturing effort while maintaining required stiffness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs composite materials, specifically carbon fiber reinforced plastic, to construct the pressure bulkhead. This composite structure achieves the required stiffness and strength without needing additional metal stiffeners, thereby reducing overall weight and manufacturing complexity while maintaining structural integrity under fuselage stress.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS10099766B2Pressurized airplane fuselage, comprising a pressure bulkhead

Publication Date: 2018.10.16 AIRBUS OPERATIONS GMBH

AI summary

A pressurized aircraft fuselage includes a pressure bulkhead installed on a fuselage structure, which forms a barrier between an internal pressurized cabin area and an outside area, wherein the edge of the pressure bulkhead is circumferentially attached to the fuselage structure by fastening means, wherein the fastening means include a pair of ring-shaped attachment frames made of an open or hollow profile, which are disposed at each side of the pressure bulkhead respectively, in order to form a clamping connection for the pressure bulkhead towards the fuselage structure.