Composite Access Opening Reinforcement Through Out-of-Plane Layup

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Solution Overview

Problem

Composite materials in large structures experience peak strain variations at isolated locations such as joints and apertures, leading to material fatigue, deformation, and premature rework due to excessive strain, which complicates manufacturing and increases weight.

Innovation Solution

Introduce out-of-plane reinforcing regions with predetermined geometric perimeters around access openings in composite components during the layup process, altering strain patterns without adding material, thereby enhancing buckling resistance and reducing peak strain.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If additional material is added to create localized build-up for reinforcing composite components against peak strain, then the strength and buckling resistance are improved, but the overall weight of the composite component significantly increases

Engineering Contradiction:
Improvebuckling resistanceVSAvoidoverall weight
Core Design Contradiction:
StrengthVSWeight of stationary object

Solution Approach 1:

The patent applies out-of-plane features during the layup process that induce reinforcing regions in the third dimension. These features create geometric variations (such as subtle curvatures or undulations) in the cured composite component that provide structural reinforcement without requiring additional material mass, thereby improving buckling resistance while maintaining weight efficiency.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent changes the geometric parameters of the composite component by introducing out-of-plane features during manufacturing. These features alter the structural parameters (such as moment of inertia and buckling characteristics) of the component, enabling enhanced strength and stability without adding material, thus resolving the contradiction between strength improvement and weight increase.

Inventive Principle:
Principle #35Parameter changes

2Strength

If additional material is added to create localized build-up for reinforcing composite components, then the buckling load is improved, but the manufacturing complexity significantly increases

Engineering Contradiction:
Improvebuckling loadVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent incorporates reinforcing features during the initial layup process by placing out-of-plane features in the mold before curing. This preliminary action ensures that the reinforcing geometry is built-in from the start, eliminating the need for subsequent complex manufacturing steps such as post-cure machining, additive manufacturing, or assembly of separate reinforcement components, thereby maintaining manufacturing simplicity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent merges the reinforcement function with the primary structural component by integrating out-of-plane features directly into the layup process. This consolidation eliminates the need for separate reinforcement elements and their associated manufacturing steps, reducing overall manufacturing complexity while achieving the desired buckling load improvement.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If out-of-plane reinforcing regions are induced during layup, then peak strain is reduced and buckling resistance is improved, but the manufacturing process becomes more complex

Engineering Contradiction:
Improvepeak strain reductionVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The out-of-plane features used to induce reinforcing regions are self-removing or self-integrating elements that are part of the mold or tooling. They automatically create the desired geometric reinforcement during the curing process and can be easily removed or integrated without requiring additional manufacturing steps, thus achieving peak strain reduction without significantly increasing manufacturing process complexity.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3888892B1Composite materials having reinforced access openings
Publication Date: 2025.07.09 THE BOEING CO
  • EP3888892B1 patent drawingFigure 1
  • EP3888892B1 patent drawingFigure 1A
  • EP3888892B1 patent drawingFigure 1B~3

AI summary

Structurally reinforced composite components are disclosed having access openings reinforced to increase strain load and buckling load without adding weight to the composite components by inducing out-of-plane regions proximate to the access opening during composite prepreg laminate layup.