Wind Turbine Blade Shear Web Spar Cap Connection

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Solution Overview

Problem

Existing wind turbine blades face challenges in providing a reliable and well-defined connection between the shear web and the blade shell, which can lead to crippling or buckling under high wind forces, and lack a robust structural reinforcement.

Innovation Solution

The wind turbine blade design features a shear web directly attached to the blade shell via a spar cap, with a male portion protruding from the shear web and a female portion in the spar cap, creating a secure connection and structural reinforcement by using composite materials like fiber-reinforced plastics or wood, and employing adhesive reservoirs for enhanced bonding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the shear web is connected to the blade shell by means of a spar cap, then the connection between shear web and blade shell is provided, but the distance between blade shells is not well defined and structural reinforcement is insufficient

Engineering Contradiction:
Improveconnection reliabilityVSAvoidstructural strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The invention merges two connection approaches into a single integrated solution: the shear web is both directly attached to the blade shell and connected via the spar cap. This dual connection method combines the advantages of direct attachment (defining distance between shells) with spar cap reinforcement (providing structural strength), thereby resolving the contradiction between connection reliability and structural strength.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The spar cap and shear web are made of fiber-reinforced plastic materials, utilizing composite material properties to achieve both reliable connection and high structural strength. The composite materials provide enhanced mechanical properties that allow the structure to withstand high wind forces while maintaining structural integrity.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If the shear web is directly attached to the blade shell, then the distance between blade shells is well defined, but the connection reliability is insufficient under high wind forces

Engineering Contradiction:
Improvedistance definitionVSAvoidconnection reliability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The invention combines direct attachment (which defines distance between shells with manufacturing precision) and spar cap connection (which provides reliability under load). This merged approach allows the structure to maintain precise geometry during manufacturing while achieving reliable connection that can withstand high wind forces during operation.

Inventive Principle:
Principle #5Merging (Combining)

3Power

If long rotor blades are used to increase power output, then the energy generation is improved, but the blades experience high wind forces causing crippling or buckling

Engineering Contradiction:
Improvepower outputVSAvoidresistance to crippling and buckling
Core Design Contradiction:
PowerVSStrength

Solution Approach 1:

The use of fiber-reinforced plastic materials in the spar cap and shear web provides high strength-to-weight ratio, enabling long rotor blades to withstand high wind forces while maintaining structural integrity. The composite materials resist crippling and buckling loads, allowing the blades to be extended for increased power output.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The spar cap structure with its curved geometry and the shear web configuration provide structural reinforcement that distributes wind loads more effectively, preventing localized stress concentrations that could lead to crippling or buckling in long blades.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP3568587B1Wind turbine blade, wind turbine and method for producing a wind turbine blade
Publication Date: 2020.11.25 SIEMENS GAMESA RENEWABLE ENERGY AS
  • EP3568587B1 patent drawingFigure 1
  • EP3568587B1 patent drawingFigure 2~3
  • EP3568587B1 patent drawingFigure 4~5

AI summary

A wind turbine blade (5) for a wind turbine (1), comprising a blade shell (9) having an inner surface (13), a shear web (16) having an end (19) and a male portion (21) protruding from the end (19), and a spar cap (17) having a female portion (23) receiving the male portion (21) of the shear web (16), wherein an end face (25) of the male portion (21) is attached to the inner surface (13) of the blade shell (9). A distance between blade shells (9, 10) is well defined. At the same time, a reliable connection between the shear web (16) and the blade shell (9) is provided.