Composite Laminate Patch Patterning for Interlaminar Crack Control

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Solution Overview

Problem

Existing composite laminates with uniformly distributed CNT interlayers experience modest increases in work of fracture due to crack deflection into the intralaminar region, failing to effectively promote crack propagation within the interlaminar region for enhanced fracture toughness.

Innovation Solution

A method of manufacturing a composite laminate with a discontinuous reinforcing patch comprising patterned nanomaterial-filled zones and vacant zones, encouraging cracks to remain in the interlaminar region by providing areas free of nanomaterial reinforcement, promoting local plastic interlaminar failure and increased fracture toughness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If uniformly distributed CNT interlayers are used, then crack deflection into intralaminar region occurs, but fracture toughness enhancement is limited

Engineering Contradiction:
Improvefracture toughnessVSAvoidcrack propagation control
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The interlayer is segmented into nanomaterial-filled zones and vacant zones, creating a discontinuous reinforcing patch. This segmentation allows cracks to experience different resistance mechanisms in different regions, with vacant zones promoting interlaminar crack propagation and nanomaterial-filled zones providing reinforcement, thereby enhancing fracture toughness while maintaining manufacturability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the interlayer are assigned different qualities: nanomaterial-filled zones provide high strength and crack bridging, while vacant zones facilitate interlaminar crack propagation. This local differentiation of properties enables the interlayer to simultaneously promote both interlaminar crack propagation and fracture toughness enhancement

Inventive Principle:
Principle #3Local quality

2Strength

If nanomaterial-filled interlayer is provided, then crack deflection occurs, but crack propagation within interlaminar region is not effectively promoted

Engineering Contradiction:
Improveinterlaminar fracture toughnessVSAvoidcrack propagation control
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The interlayer is divided into discrete nanomaterial-filled zones separated by vacant zones. This segmentation creates a patterned structure where cracks can propagate through vacant zones along the interlaminar region while being arrested or deflected by nanomaterial-filled zones, thereby reliably controlling crack propagation paths and enhancing interlaminar fracture toughness

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The discontinuous reinforcing patch acts as an intermediary structure between the plies, with vacant zones serving as mediators that facilitate interlaminar crack propagation and nanomaterial-filled zones serving as mediators that provide reinforcement and energy dissipation, thereby achieving reliable crack propagation control

Inventive Principle:
Principle #24Intermediary (Mediator)

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 discontinuous reinforcing patch design enhances interlaminar fracture toughness by facilitating energy-dissipating mechanisms like rupture and pull-out, resulting in higher laminate strength and improved crack propagation within the interlaminar region.

Implementation Method 1

facilitating energy-dissipating mechanisms like rupture and pull-out

Methodology Applied
Scientific EffectRupture: Fracture Mechanics

Implementation Method 2

facilitating energy-dissipating mechanisms like rupture and pull-out

Methodology Applied
Scientific EffectPull-out: Friction

Implementation Method 3

promoting local plastic interlaminar failure

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP4183560B1Method of manufacturing a composite laminate
Publication Date: 2026.03.11 ROLLS ROYCE PLC
  • EP4183560B1 patent drawingFigure 1~2
  • EP4183560B1 patent drawingFigure 3
  • EP4183560B1 patent drawingFigure 4A~4B

AI summary

A method of manufacturing a composite laminate. The method comprises providing a base layer, providing a discontinuous reinforcing patch on the base layer, and providing a top layer over the base layer and discontinuous reinforcing patch. A composite laminate having a discontinuous reinforcing patch interposed between a base layer and a top layer is also disclosed. The discontinuous reinforcing patch comprises a patterned nanomaterial layer with nanomaterial-filled zones and vacant zones.