Segmented Wind Turbine Blade Joint With Nested Spar Reinforcement

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Solution Overview

Problem

Challenges in manufacturing and joining segmented wind turbine blades, particularly in achieving the desired strength and aerodynamic properties in the connection area between spar parts, leading to increased manufacturing and transportation costs.

Innovation Solution

A method for manufacturing a segmented wind turbine blade with a female spar part and a male spar part connection, utilizing a chordwise joint and secondary spar cap portions affixed to the female spar part's outer surface, along with a locking mechanism, to ensure structural integrity and minimal impact on blade performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If wind turbine blades are segmented into multiple segments, then manufacturing and transportation costs are reduced and ease of manufacture is improved, but the strength and structural integrity of the connection area between segments deteriorates

Engineering Contradiction:
Improveease of manufactureVSAvoidstrength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The wind turbine blade is divided into multiple segments that can be manufactured and transported separately, then assembled at the erection site. This segmentation enables easier manufacturing and reduced transportation costs while maintaining the overall structural integrity through proper connection designs.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The connection area between blade segments utilizes a nested structure where a male spar part fits into a female spar part cavity. This nesting approach provides a strong mechanical interlock that maintains structural integrity while enabling modular assembly. The secondary spar cap portions are affixed to the outer surface of the female spar part, creating a multi-layer nested connection that distributes loads effectively.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of manufacture

If blade segments are assembled with connection structures, then ease of manufacture and transportation are improved, but the aerodynamic properties and blade performance in the connection area deteriorate

Engineering Contradiction:
Improveease of manufactureVSAvoidblade performance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The connection area is designed with localized reinforcement features including secondary spar cap portions affixed to the outer surface of the female spar part. These local quality enhancements ensure that the connection area maintains the necessary aerodynamic properties and structural performance while enabling modular assembly. The locking mechanism provides localized mechanical interlock without disrupting the overall aerodynamic profile.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The connection area acts as an intermediary zone between blade segments, designed to transition smoothly between segments while maintaining aerodynamic continuity. The locking mechanism and secondary spar cap portions serve as intermediary structural elements that provide mechanical connection without creating significant aerodynamic disturbances, thus preserving blade performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If the connection area between spar parts is reinforced to achieve desired strength, then structural integrity is improved, but the manufacturing complexity and device complexity increase

Engineering Contradiction:
Improvestructural strengthVSAvoiddevice complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The spar cap is divided into primary and secondary portions, with the secondary spar cap portions being affixed to the female spar part. This segmentation allows for modular manufacturing and assembly, reducing overall device complexity while achieving the desired structural strength through the distributed reinforcement of multiple components working together.

Inventive Principle:
Principle #1Segmentation

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

The solution provides a segmented wind turbine blade with enhanced structural strength and aerodynamic properties, facilitating easier manufacturing and reduced transportation costs while maintaining blade performance.

Implementation Method 1

infusing the first shell portion and the first primary spar cap portion with a resin connecting the first primary spar cap portion to an inner surface of the first shell portion

Methodology Applied
Scientific EffectResin infusion: Adhesive

Implementation Method 2

a locking mechanism for locking the female spar part and the male spar part together

Methodology Applied
Scientific EffectMechanical locking: Mechanical Fastener

Data Source

PatentEP4174310B1Segmented wind turbine blade
Publication Date: 2026.03.25 LM WIND POWER AS
  • EP4174310B1 patent drawingFigure 1
  • EP4174310B1 patent drawingFigure 2
  • EP4174310B1 patent drawingFigure 3

AI summary

The present disclosure relates to a method for manufacturing a blade segment for a segmented wind turbine blade, and a resulting segment for a segmented wind turbine blade as well as the segmented wind turbine blade. In particular, the blade segment comprises a female spar part defining an inner cavity and having a longitudinal inner end and an opposite longitudinal open end towards an end face of the blade segment, a first spar cap connected to an inner surface of a first shell portion and comprising a first primary spar cap portion. The blade segment further comprises a first secondary spar cap portion affixed to a first outer surface of the female spar part. The first secondary spar cap portion is glued to the inner surface of the first shell portion and/or to the first primary spar cap portion forming a glue interface between the first secondary spar cap portion and the inner surface of the first shell portion and/or the first primary spar cap portion.