Wind Turbine Blade Insert Connection Structure

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Solution Overview

Problem

Existing connection structures for wind turbine blades face challenges in ensuring proper fiber reinforcement between embedded metal inserts, often resulting in weak spots due to gaps and increased manufacturing costs, particularly with the use of spacers and grooves that can weaken the composite material.

Innovation Solution

A method involving wrapping elongate inserts with a fibre mat that exceeds their length, ensuring good contact with inner layers, and manufacturing deformable spacers as simple wound coils to fill gaps between inserts, reducing the need for specialized equipment and minimizing weak spots.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If spacers and grooves are used to ensure fiber contact between inserts, then manufacturing precision is improved, but device complexity increases and strength decreases

Engineering Contradiction:
Improvefiber contact between insertsVSAvoidstructure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention removes the complex spacer and groove components from the insert design. Instead of adding these auxiliary structures, the solution extracts only the essential cylindrical body with threaded bore, relying on the laminate layers themselves to provide the necessary fiber contact and structural function.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Rather than modifying the insert to include grooves or spacers to achieve fiber contact, the invention inverts the approach by allowing the natural laminate construction process to provide the fiber reinforcement. The fiber mats are placed directly against the insert surfaces during lamination, eliminating the need for insert modifications.

Inventive Principle:
Principle #13The other way round (Inversion)

2Manufacturing precision

If spacers and grooves are used to ensure fiber contact between inserts, then manufacturing precision is improved, but strength worsens due to weak spots in composite material

Engineering Contradiction:
Improvefiber contact between insertsVSAvoidcomposite material strength
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The invention removes the groove features from the insert design that create stress concentration points and weak spots in the composite. By extracting this problematic geometric feature while retaining the essential threaded bore functionality, the solution eliminates the source of structural weakness.

Inventive Principle:
Principle #2Taking out (Extraction)

3Quantity of substance

If metal wool layer is used to cover inserts, then fiber concentration in gaps is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvefiber concentration in gapsVSAvoidmanufacturing process complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The invention removes the metal wool layer from the insert design. Instead of adding this auxiliary fiber-providing component, the solution extracts the problem entirely by designing inserts that work effectively with standard laminate construction processes using conventional fiber mats.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the expensive and complex metal wool covering with simple, inexpensive standard fiber mats that are already part of the laminate construction process. These conventional fiber materials provide sufficient reinforcement without requiring special handling or expensive materials.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

4Area of stationary object

If longitudinal grooves are provided in inserts, then bonding surface area is improved, but manufacturing cost increases substantially

Engineering Contradiction:
Improvebonding surface areaVSAvoidinsert manufacturing cost
Core Design Contradiction:
Area of stationary objectVSEase of manufacture

Solution Approach 1:

The invention removes the longitudinal groove features from the insert design. By extracting this cost-increasing geometric modification while retaining the essential threaded bore functionality, the solution eliminates the substantial manufacturing cost increase associated with groove production.

Inventive Principle:
Principle #2Taking out (Extraction)

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 ensures a high concentration of fibers in the adhesion zone, reduces manufacturing costs, and simplifies the process by allowing prep work during curing, resulting in a stronger and more cost-effective connection structure.

Implementation Method 1

impregnating the fibre mat layers with curable resin, and curing the resin

Methodology Applied
Scientific EffectResin infusion and curing: Photopolymerisation

Data Source

PatentEP3468781B1A connection structure of a wind turbine blade and method for its manufacture
Publication Date: 2022.08.03 NORDEX BLADE TECH CENT APS
  • EP3468781B1 patent drawingFigure 1~2
  • EP3468781B1 patent drawingFigure 3~4
  • EP3468781B1 patent drawingFigure 5a~5h

AI summary

A method for manufacturing a connection structure (1) of a wind turbine blade part. The method comprises the following steps. Providing an elongate insert (8) with a predetermined length, said insert (8) comprising at least one cylindrical part and one tapered part. The at least one cylindrical part comprises an end face from which a centrally arranged threaded bore (9) extends towards the tapered part. Providing a fibre mat (7) of a predetermined shape which at least in one direction is longer than the predetermined length of said elongate insert(8). Wrapping said elongate insert (8) in said fibre mat (7). Embedding said wrapped elongate insert (8) between further layers of fibre (6, 10) mat of said connection structure (1). Impregnating the fibre mat layers with curable resin, and curing the resin.