Wind Turbine Rotor Blade Joint Interface Design

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Solution Overview

Problem

The existing joint structures between spar caps and shear webs in wind turbine rotor blades are limited by the reliance on adhesive strength, which can be insufficient to handle the increasing loads and stiffness requirements of longer blades.

Innovation Solution

The implementation of a novel joint interface configuration using a plurality of webs, which are bonded to the outer surfaces of the structural components and woven between pultruded members, to enhance the structural integrity and load transfer capabilities between the spar caps and shear webs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional adhesive bonds are used to join spar caps and shear webs, then the joint structure is simple and easy to manufacture, but the joint strength and load transfer capability are insufficient for longer blades

Engineering Contradiction:
Improvejoint strengthVSAvoidjoint structure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The joint interface is segmented into multiple functional zones with different reinforcement strategies. The first region uses adhesive bonding, the second region introduces mechanical interlocking through webs, and the third region employs pultruded composite reinforcement. This segmentation allows each zone to be optimized for its specific function while collectively achieving the required joint strength.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention employs composite materials in multiple forms: adhesive composites for bonding, fabric reinforcement composites in the web regions, and pultruded composite members for structural reinforcement. These composite materials work together to create a multi-scale reinforcement system that significantly enhances joint strength beyond what adhesive alone could provide.

Inventive Principle:
Principle #40Composite materials

2Power

If blade length is increased to produce more power, then energy production increases, but the blade becomes more susceptible to bending moments and loads

Engineering Contradiction:
Improvepower productionVSAvoidbending resistance
Core Design Contradiction:
PowerVSStrength

Solution Approach 1:

The joint interface is pre-reinforced with multiple layers of reinforcement elements including adhesive, fabric webs, and pultruded members before the blade operates under load. This preliminary reinforcement structure is built into the blade during manufacturing, providing enhanced bending resistance from the outset to accommodate longer blade lengths and higher power production requirements.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If pultruded spar caps are used, then manufacturing defects are reduced and weight is decreased, but the joint interface with shear web remains a structural limitation

Engineering Contradiction:
Improvemanufacturing reliabilityVSAvoidjoint interface strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The joint interface is segmented into multiple functional zones with different reinforcement strategies. The first region uses adhesive bonding, the second region introduces mechanical interlocking through webs, and the third region employs pultruded composite reinforcement. This segmentation allows each zone to be optimized for its specific function while collectively achieving the required joint strength.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention employs composite materials in multiple forms: adhesive composites for bonding, fabric reinforcement composites in the web regions, and pultruded composite members for structural reinforcement. These composite materials work together to create a multi-scale reinforcement system that significantly enhances joint strength beyond what adhesive alone could provide.

Inventive Principle:
Principle #40Composite materials

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 improved joint interface structure provides a stronger and more reliable connection, enabling the transfer of larger loads and allowing for the design of lighter, less costly, or longer wind turbine blades without reaching material limits, thereby reducing the overall cost of electricity production.

Implementation Method 1

the resin cures or undergoes polymerization through added heat or other curing methods

Methodology Applied
Scientific EffectPolymerization: Photopolymerisation

Implementation Method 2

this joint relies primarily on the strength of an adhesive or resin deposited at the interface of the components

Methodology Applied
Scientific EffectAdhesive bonding: Adhesive

Data Source

PatentEP3857052B1Joint interface for wind turbine rotor blade components
Publication Date: 2025.05.21 GENERAL ELECTRIC RENOVABLES ESPANA SL
  • EP3857052B1 patent drawingFigure 1
  • EP3857052B1 patent drawingFigure 2~3
  • EP3857052B1 patent drawingFigure 4~5

AI summary

A rotor blade component for a wind turbine includes a first structural component, such as a spar cap, formed from a plurality of stacked pultruded members. A second structural component, such as a shear web, is fixed to the first structural component at a joint interface. One or more webs form the joint interface, wherein each of the webs has a first section bonded between at least two of the pultruded members in the first structural component and a second section extending across the joint interface and bonded onto or into the second structural component.