Spacer Material for Wind Turbine Segmented Rotor Blade Bond Gap

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Solution Overview

Problem

The existing segmented rotor blades in wind turbines face challenges due to bond gaps between the beam structure and the blade shell, which can lead to increased production costs, delamination risks, and the need for undesirable repair procedures.

Innovation Solution

The introduction of spacer materials between the beam structure and the blade shell reduces the bond gap, improving the structural integrity and reducing production costs by minimizing delamination risks and the need for repairs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a tapered beam structure is used to fit within the receiving section, then the beam structure can be received in the second blade segment, but a gap is created between the beam structure and the inner pressure and/or suction side surfaces of the shell halves

Engineering Contradiction:
Improvebeam structure fitVSAvoidbond gap
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

A foam material is introduced as an intermediary substance between the tapered beam structure and the shell halves. The foam material fills the gap created by the tapered beam configuration, providing a bonding medium that eliminates the harmful bond gap while accommodating the adaptive tapered shape of the beam structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The foam material undergoes a parameter change from a liquid or semi-liquid state to a solid foam structure. This phase change allows the material to flow into the gap space and then solidify to provide structural support and eliminate the bond gap, transforming the harmful void into a beneficial bonding medium.

Inventive Principle:
Principle #35Parameter changes

2Strength

If the beam structure is made of structurally stiff materials such as carbon fiber composites, then the beam structure achieves high strength and stiffness, but the material becomes difficult to manipulate within the scarf joint, further contributing to the size of the gap

Engineering Contradiction:
Improvebeam structure strengthVSAvoidbeam structure manipulation
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The foam material serves as a mediator that compensates for the difficulty of manipulating stiff carbon fiber beam structures. By providing a gap-filling bonding medium, the foam eliminates the need for precise manipulation of the rigid beam structure, allowing easier assembly while maintaining high structural strength.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If a large bond gap exists between the beam structure and shell halves, then the bond dimension increases, but this increases the risk of delamination, production costs, and may necessitate repair procedures

Engineering Contradiction:
Improvebond dimensionVSAvoiddelamination risk
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The foam material converts the harmful bond gap into a beneficial bonding medium. Rather than leaving the gap as a void that promotes delamination, the foam fills the space and creates a strong bonding interface, transforming the defect into a strength-enhancing feature.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The foam material utilizes its porous structure to effectively fill the bond gap. The porous nature of the foam allows it to conform to the irregular gap geometry while providing sufficient structural integrity to eliminate delamination risks and reduce bond dimension complexity.

Inventive Principle:
Principle #31Porous materials

Data Source

PatentEP3873728B1Spacer material for reducing a bond gap between a beam structure and a blade shell of a segmented rotor blade
Publication Date: 2025.05.21 GENERAL ELECTRIC RENOVABLES ESPANA SL
  • EP3873728B1 patent drawingFigure 1
  • EP3873728B1 patent drawingFigure 2~3
  • EP3873728B1 patent drawingFigure 4~5

AI summary

A rotor blade for a wind turbine including first and second blade segments extending in opposite directions from a chord-wise joint. The first and second blade segments include one or more shell members and internal support structures coupled to an inner surface of the one or more shell members of the first and second blade segments. The internal support structure of the first blade segment includes a beam structure extending between a first end at the chord-wise joint and a second end such that the beam structure is received by a receiving section of the internal support structure of the second blade segment. The rotor blade includes one or more spacer materials arranged within the first blade segment between an exterior surface of the beam structure and the inner surface of the one or more shell members to reduce a bond gap therebetween.