Wind Turbine Blade Internal Web Pre-Curing

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Solution Overview

Problem

Conventional methods for assembling wind turbine blades with internal webs face issues due to thermal distortions during the curing process, leading to potential delamination or adhesive voids that compromise the structural integrity of the blades.

Innovation Solution

A method and apparatus that involves pre-curing the adhesive bonds between the internal web and the outer shell portions using localized heat energy before full curing, ensuring the adhesive bond can withstand thermal deformations and stresses, thereby maintaining bond integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If adhesive bonds are cured using heated mould and heated air during the bond line curing step, then the adhesive material is cured and elements are bonded together, but thermal distortions occur in the outer shell portions causing delamination or adhesive voids

Engineering Contradiction:
Improveadhesive bond integrityVSAvoidthermal distortions
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by pre-positioning and pre-curing the internal web to the first outer shell portion before the final assembly with the second outer shell portion. This preliminary bonding creates a stable structural core that resists thermal distortions during subsequent curing operations, preventing delamination and adhesive voids that would occur if all elements were bonded simultaneously during high-heat curing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The curing process is segmented into multiple stages: first, the internal web is bonded to the first outer shell portion and cured; then the second outer shell portion is added and bonded. This segmentation allows each bonding operation to be optimized independently, with the first bond established under controlled conditions before thermal curing begins, thereby preventing thermal distortions from compromising bond integrity.

Inventive Principle:
Principle #1Segmentation

2Strength

If internal webs are added to strengthen the wind turbine blade, then the blade rigidity and strength are improved, but the assembly complexity and manufacturing difficulty increase

Engineering Contradiction:
Improveblade rigidityVSAvoidassembly complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The internal web is pre-positioned and pre-cured to the first outer shell portion before final assembly. This preliminary action simplifies the overall manufacturing process by creating a stable intermediate structure that is easier to handle and align during subsequent steps, reducing assembly complexity while maintaining the strength benefits of the internal web reinforcement.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies local quality by providing structural reinforcement (internal web) only where needed within the blade structure, rather than uniformly throughout. This allows the blade to achieve necessary rigidity and strength in critical areas while keeping the overall design and assembly process manageable and cost-effective.

Inventive Principle:
Principle #3Local quality

3Reliability

If the second outer shell portion is closed over the internal web and first outer shell portion during curing, then the blade structure is finalized, but thermal distortions compromise the adhesive bond between the internal web and second outer shell portion

Engineering Contradiction:
Improveadhesive bond reliabilityVSAvoidbond positioning accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The internal web is pre-positioned and pre-cured to the first outer shell portion with high precision before the second outer shell portion is added. This preliminary bonding establishes accurate positioning and creates a stable reference structure that maintains bond positioning accuracy even when thermal distortions occur during final curing with the second shell portion.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The pre-cured internal web acts as a cushioning element that absorbs and compensates for thermal distortions occurring during final curing. By establishing the first bond beforehand under controlled conditions, the structure is cushioned against subsequent thermal stresses, maintaining bond integrity and positioning accuracy despite thermal expansion and contraction during final assembly.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 pre-curing process enhances the reliability of the adhesive bond between the internal web and the outer shell portions, reducing the risk of delamination and adhesive voids, resulting in a more structurally reliable wind turbine blade.

Implementation Method 1

A localized heating device is provided for pre-curing an adhesive material at a top end of the internal web with application of thermal energy

Methodology Applied
Scientific EffectThermal energy application: Heating

Implementation Method 2

pre-curing an adhesive material at a top end of the internal web with application of thermal energy to bond the top end of the internal web to one of the first and second outer shell portions

Methodology Applied
Scientific EffectAdhesive bonding: Adhesive

Data Source

PatentEP3568287B1Method and apparatus for assembling a wind turbine blade having an internal web
Publication Date: 2021.08.18 VESTAS WIND SYSTEMS AS
  • EP3568287B1 patent drawingFigure 1
  • EP3568287B1 patent drawingFigure 2
  • EP3568287B1 patent drawingFigure 3A~3B

AI summary

A method and apparatus for assembling a wind turbine blade (10) including first and second outer shell portions (16, 18) and an internal web (12) are provided. An adhesive material (42) is applied to a top end (30) of the internal web (12) as well as the edges (62, 64) of the first outer shell portion (16) for connection to the second outer shell portion (18). Localized heat energy is applied to pre-cure the adhesive material (42) at the top end (30) of the internal web (12) before applying heat energy to fully cure all of the adhesive material (42) in the wind turbine blade (10). The pre-curing is performed by a removable localized heater device (72), and it assures that the integrity of the bond between the internal web (12) and the second outer shell portion (18) is maintained during the full curing of the blade (10), when temporary thermal deformation of the outer shell (14) sometimes occurs.