Hybrid Adhesive Joint for Large-Gap Structural Connections

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Solution Overview

Problem

In the construction industry, traditional adhesive connections between structural components, such as metallic tubes, face challenges due to significant manufacturing and dimensional tolerances, leading to large gap dimensions that require extensive adhesive use, increased costs, and susceptibility to errors under adverse construction site conditions, resulting in decreased durability and stress inhomogeneities.

Innovation Solution

A hybrid adhesive connection is developed using a combination of an organic adhesive layer with embedded solid particles and an inorganic filler material, such as grout, where the adhesive layer is applied and cured in controlled conditions before assembly on-site, ensuring a strong and reliable bond across varying gap widths and surface geometries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If adhesive connections are used to join structural components with large gap dimensions (3-15 mm), then the connection can accommodate manufacturing and dimensional tolerances, but the durability decreases and the amount of adhesive required increases enormously

Engineering Contradiction:
Improvegap dimension toleranceVSAvoidconnection durability
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The patent uses a composite connection system combining organic adhesive material and inorganic filling material (grout or mortar). The organic adhesive provides bonding strength while the inorganic filler stabilizes the thick adhesive layer and improves durability. This composite approach allows large gap dimensions (3-15 mm) to be accommodated while maintaining connection durability and reducing the required amount of expensive organic adhesive.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If large amounts of standard quality adhesive are used to fill large gaps, then the gap can be bridged, but the costs increase enormously

Engineering Contradiction:
Improvegap bridging capabilityVSAvoidadhesive quantity
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent replaces large amounts of expensive organic adhesive with a composite system where inorganic filling material (grout or mortar) serves as the primary gap-filling substance. The organic adhesive is used only as a bonding agent in combination with the filler, dramatically reducing the quantity of organic adhesive required while maintaining gap bridging capability for dimensions up to 15 mm and more.

Inventive Principle:
Principle #40Composite materials

3Ease of operation

If adhesive connections are carried out on site under adverse construction site conditions, then the connection can be made in the field, but the susceptibility to errors increases

Engineering Contradiction:
Improveon-site applicabilityVSAvoidconnection error susceptibility
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent allows the organic adhesive to be applied and cured in controlled factory conditions before assembly, creating a pre-bonded component. This preliminary action in a controlled environment reduces susceptibility to on-site construction conditions and errors. The pre-cured adhesive layer is then assembled with other components on-site, combining the benefits of controlled manufacturing with field applicability.

Inventive Principle:
Principle #10Preliminary action

4Strength

If thin-layer adhesive bonding is used as in automobile construction, then the connection is strong, but it cannot be carried out in the construction industry due to considerable manufacturing and dimensional tolerances

Engineering Contradiction:
Improveadhesive bond strengthVSAvoidtolerance to manufacturing variations
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The patent creates a hybrid adhesive connection combining organic adhesive material with inorganic filling material (grout or mortar). This composite system maintains the bonding strength of thin-layer adhesive while accommodating large gap dimensions (3-15 mm) typical in construction. The inorganic filler provides structural stability and allows the connection to tolerate manufacturing and dimensional variations that would prevent thin-layer bonding in construction applications.

Inventive Principle:
Principle #40Composite materials

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 solution significantly enhances the load-bearing capacity and fatigue strength of the connection while reducing costs and error susceptibility, allowing for reliable assembly under construction site conditions without harmful heat input, and providing improved bonding and stress distribution.

Implementation Method 1

at least one of the joining surfaces is wetted with a preferably organic adhesive layer

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

the remaining joining gap is wetted with an inorganic or organic filler material

Methodology Applied
Scientific EffectGravitation: Gravitation

Data Source

PatentEP3237765B1Connection between two joining partners, and method for establishing said connection
Publication Date: 2022.05.25 KARLSRUHER INST FUR TECH
  • EP3237765B1 patent drawingFigure 1~2a
  • EP3237765B1 patent drawingFigure 2b~2d
  • EP3237765B1 patent drawingFigure 3~4

AI summary

Disclosed is a connection between at least two joining partners (1, 4), comprising an interstitial joint (7) that has opposite joint surfaces (2, 5). At least one of the joint surfaces is wetted with an adhesive layer (3, 6) containing incorporated and/or attached solid particles (11, 12), and the remainder of the joint is filled with an inorganic and/or organic filler (8).