Aircraft Inlet Bulkhead Composite Structure for Bird Strike Absorption

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Solution Overview

Problem

Aircraft propulsion systems are susceptible to high-velocity impacts from bird strikes, and existing propulsion system housings lack adequate resistance to such impacts, necessitating improved structural integrity and energy absorption.

Innovation Solution

The air inlet bulkhead assembly incorporates a thermoplastic composite material with a flexible woven fabric layer embedded in a thermoplastic matrix, featuring a rigid first bulkhead portion and a flexible second bulkhead portion to provide structural support and absorb impact energy from bird strikes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a rigid propulsion system housing is used, then structural integrity is improved, but weight increases and energy absorption capability deteriorates

Engineering Contradiction:
Improvestructural integrityVSAvoidhousing weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The bulkhead assembly combines rigid thermoplastic composite material for structural support with flexible woven fabric material for energy absorption. This composite construction allows the housing to maintain structural integrity while reducing weight and improving impact energy absorption capability compared to purely rigid housings.

Inventive Principle:
Principle #40Composite materials

2Strength

If a rigid propulsion system housing is used, then structural integrity is improved, but impact energy absorption deteriorates

Engineering Contradiction:
Improvestructural integrityVSAvoidimpact energy absorption
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The bulkhead assembly combines rigid thermoplastic composite material for structural support with flexible woven fabric material for energy absorption. This composite construction allows the housing to maintain structural integrity while improving impact energy absorption capability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The bulkhead assembly uses different materials with different properties in different regions: rigid thermoplastic composite for structural support and flexible woven fabric for energy absorption. This local differentiation of material properties allows the housing to simultaneously maintain structural integrity and improve impact energy absorption.

Inventive Principle:
Principle #3Local quality

3Weight of moving object

If lightweight materials are used, then weight is reduced, but structural integrity deteriorates

Engineering Contradiction:
Improvehousing weightVSAvoidstructural integrity
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The bulkhead assembly uses thermoplastic composite material and flexible woven fabric, which are lighter than traditional rigid metals but maintain structural integrity through their composite structure. The rigid thermoplastic composite provides necessary strength while the flexible fabric layer adds energy absorption capability.

Inventive Principle:
Principle #40Composite materials

4Device complexity

If a single-material bulkhead is used, then device complexity is reduced, but impact resistance deteriorates

Engineering Contradiction:
Improvebulkhead structureVSAvoidimpact resistance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The bulkhead assembly uses a composite structure with rigid thermoplastic composite material and flexible woven fabric material, each serving specific functions. This multi-material approach enhances impact resistance by combining the structural support capability of the rigid material with the energy absorption capability of the flexible material.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The bulkhead is divided into two distinct portions: a first bulkhead portion made of rigid thermoplastic composite material for structural support, and a second bulkhead portion made of flexible woven fabric for energy absorption. This segmentation allows each portion to optimize its specific function, improving overall impact resistance.

Inventive Principle:
Principle #1Segmentation

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 assembly effectively reduces the transmission of bird strike impact energy to the outer and inner skins while maintaining structural integrity, facilitating lightweight construction and energy absorption.

Implementation Method 1

The assembly effectively reduces the transmission of bird strike impact energy to the outer and inner skins while maintaining structural integrity, facilitating lightweight construction and energy absorption.

Methodology Applied
Scientific EffectEnergy absorption: Deformation

Implementation Method 2

Aircraft propulsion systems are susceptible to high-velocity impacts from bird strikes, and existing propulsion system housings lack adequate resistance to such impacts, necessitating improved structural integrity and energy absorption.

Methodology Applied
Scientific EffectImpact force: Impact Force

Data Source

PatentEP4406850B1Air inlet bulkhead assembly for an aircraft propulsion system
Publication Date: 2026.02.25 ROHR INC
  • EP4406850B1 patent drawingFigure 1~2
  • EP4406850B1 patent drawingFigure 3
  • EP4406850B1 patent drawingFigure 4~5

AI summary

An air inlet (40) for an aircraft propulsion system nacelle (24) includes an outer skin (44), an inner skin (46), a lip skin (48), and a forward bulkhead (50). The lip skin (48) extends between and to an outer end (62) and an inner end (64). The outer end (62) is disposed at the outer skin (44). The inner end (64) is disposed at the inner skin (46). The forward bulkhead (50) includes a first bulkhead portion (76) and a second bulkhead portion (78). The first bulkhead portion (76) and the second bulkhead portion (78) are mounted to the outer skin (44). The first bulkhead portion (76) and the second bulkhead portion (78) are mounted to the inner skin (46). The first bulkhead portion (76) includes a rigid body material and the second bulkhead portion (78) includes a flexible body material.