Single-Shear Node Joint With Vacuum-Assisted Adhesive Sealing

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Solution Overview

Problem

Existing node-to-node connection techniques in 3D printing lack efficient methods for forming strong, reliable bonds between additively manufactured components, particularly in complex geometries and mechanical structures like vehicles and aircraft, where traditional methods fail to provide consistent mechanical properties and hermetic seals.

Innovation Solution

A method involving the additive manufacturing of nodes with bonding surfaces, fixturing for adhesive injection, and using vacuum to evacuate the bonding region before injecting adhesive through specifically designed features to form a single shear adhesive bond, ensuring a strong and sealed connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If traditional connection techniques are used for node-to-node connections in 3D printing, then manufacturing simplicity is maintained, but bond strength and hermetic seal reliability are insufficient

Engineering Contradiction:
Improvebond strengthVSAvoidconnection structure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The connection structure is divided into distinct functional elements: bonding surfaces on nodes, separate adhesive bonding regions, and hermetic seal features. This segmentation allows each element to be optimized independently for its specific function while maintaining overall connection strength and reliability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bonding surfaces are prepared in advance during additive manufacturing with specific surface characteristics (flatness, area, orientation) to ensure optimal adhesive bonding. The vacuum port and adhesive port features are also pre-configured in the node designs to facilitate the bonding process

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If complex geometries and internal lattice structures are implemented in nodes, then design versatility is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvedesign flexibilityVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The additive manufacturing process is used to create nodes that simultaneously achieve complex geometries, internal lattice structures, precise bonding surfaces, and integrated port features. This single process accomplishes multiple functions that would require separate operations with traditional manufacturing methods

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The additive manufacturing process enables continuous variation of geometric parameters within nodes, including lattice cell sizes, wall thicknesses, and bonding surface characteristics. This allows optimization of both mechanical properties and manufacturing efficiency through parameter adjustment rather than redesign

Inventive Principle:
Principle #35Parameter changes

3Reliability

If adhesive injection through vacuum-evacuated bonding regions is used, then hermetic seal reliability is improved, but process complexity increases

Engineering Contradiction:
Improvehermetic seal reliabilityVSAvoidbonding process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The vacuum port serves as an intermediary mechanism to evacuate air from the bonding region before adhesive injection. This creates a pressure differential that ensures complete adhesive filling of the bonding region and eliminates voids, improving hermetic seal reliability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The bonding process utilizes pressure differentials created by vacuum evacuation and subsequent adhesive injection. The pressure control during adhesive injection ensures proper filling of the bonding region while maintaining hermetic seal integrity

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 enables the formation of robust, hermetically sealed connections with suitable mechanical properties, suitable for complex geometries and reducing the risk of galvanic corrosion, while allowing for intricate designs and internal lattice structures not possible with traditional manufacturing.

Implementation Method 1

drawing vacuum to evacuate a bonding region

Methodology Applied
Scientific EffectVacuum: Vacuum

Implementation Method 2

the adhesive couples the first bonding surface to the second bonding surface

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3765776B1Single shear joint for node-to-node connections
Publication Date: 2024.07.10 DIVERGENT TECHNOLOGIES INC
  • EP3765776B1 patent drawingFigure 1A
  • EP3765776B1 patent drawingFigure 1B
  • EP3765776B1 patent drawingFigure 1C

AI summary

One aspect is an apparatus including a first node including a first bonding surface and a second node including a second bonding surface. The apparatus includes a feature configured to accept an adhesive and an adhesive channel coupled to the feature configured to accept the adhesive. The apparatus includes a shear joint coupling the first node and the second node, the shear joint configured to receive the adhesive in an adhesive region formed by the first bonding surface and the second bonding surface, the adhesive for coupling the first bonding surface to the second bonding surface through the feature configured to accept the adhesive.