Composite Bonding with Multi-Directional Protruding Members

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for bonding composite materials, such as those used in aircraft components, face challenges in suppressing delamination between layers, particularly when pins inserted to enhance strength can fall out.

Innovation Solution

A method involving the placement of protruding members with protrusions in different directions on the surface of composite materials, which are then introduced into the layers to bond them together, using a thermoplastic resin that is heated and cooled to cure and secure the bond.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If pins are inserted through prepreg layers to increase strength along lamination direction, then delamination is suppressed, but the pins may fall out from the composite material layers

Engineering Contradiction:
Improvestrength along lamination directionVSAvoidretention of pins in composite material layers
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention transitions from simple pin insertion to a three-dimensional protruding structure with multiple protrusions extending in different directions. This dimensional complexity prevents the fastening element from falling out by creating mechanical interlocking in multiple directions rather than a single linear path

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

Solution Approach 2:

The protruding member is formed as a composite structure combining resin and reinforcing fibers, creating a material that is both strong and capable of bonding with the composite material layers. This composite construction enhances both the strength along lamination direction and the reliability of retention

Inventive Principle:
Principle #40Composite materials

2Reliability

If multiple protrusions are added to protruding members to prevent falling out, then retention is improved, but the complexity of the protruding member structure increases

Engineering Contradiction:
Improveretention of protruding membersVSAvoidstructure of protruding members
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention merges multiple protrusions into a single integrated protruding member formed from one piece of composite material. This combining approach achieves the retention benefits of multiple protrusions while avoiding the complexity of assembling separate components, as the entire structure is formed as a unified element

Inventive Principle:
Principle #5Merging (Combining)

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 approach effectively suppresses delamination by physically fastening the composite materials with protruding members, enhancing adhesion and maintaining the bond strength.

Implementation Method 1

the introduction step includes heating and melting the resin with which the first composite material and the second composite material are each impregnated to introduce the protruding members into the interiors of the first composite material and the second composite material

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

the bonding step includes cooling the resin with which the first composite material and the second composite material are each impregnated to cure the resin

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP3705271B1Method for bonding composite material
Publication Date: 2022.04.06 MITSUBISHI HEAVY IND LTD
  • EP3705271B1 patent drawingFigure 1
  • EP3705271B1 patent drawingFigure 2
  • EP3705271B1 patent drawingFigure 3

AI summary

A method for bonding a composite material (10), in which resin is impregnated in a reinforcing fiber-containing first composite material (12) and a second composite material (14) to bond the same, comprises: a protruding member placement step for disposing multiple protruding members (16), which have multiple protrusions that protrude in mutually different directions, on the surface (12A) of the first composite material (12); a second composite material placement step for disposing the second composite material (14) on a site of the surface (12A) of the first composite material (12) where the protruding members (16) have been disposed; an introduction step for introducing the protruding members (16) into the first composite material (12) and into the second composite material (14) while bringing the first composite material (12) into contact with the second composite material (14); and a bonding step for bonding the first composite material (12) to the second composite material (14) with the protruding members (16) introduced therein by curing the resin impregnated in the first composite material (12) and the second composite material (14).