Wind Turbine Blade Transition Piece With C-Shaped Bonding Flange

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Solution Overview

Problem

The manufacturing of wind turbine rotor blades with a transition area between a blunt trailing edge and a sharp trailing edge results in thick adhesive joints that are difficult to control, leading to potential damage such as cracking, and existing solutions using core materials compromise bonding quality and structural integrity.

Innovation Solution

A transition piece with a C-shaped bonding flange and a monolithic wedge is integrated between the half-shells, ensuring a consistent adhesive joint thickness and allowing for ultrasonic inspection, using fiber composite materials to enhance structural integrity and bonding quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the transition area is laminated with thickening laminates to meet adhesive gap requirements, then the bonding quality is improved, but the manufacturing complexity and labor time increase significantly

Engineering Contradiction:
Improveadhesive gap controlVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

A transition piece acts as an intermediary element between the blunt trailing edge and the sharp trailing edge sections. This transition piece includes a C-shaped bonding flange that provides a standardized bonding surface, enabling precise adhesive gap control without requiring complex thickening laminates. The intermediary structure mediates the geometric transition while maintaining consistent bonding conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the geometric parameters of the transition area by introducing a C-shaped bonding flange with specific dimensions. This allows the adhesive gap to be controlled within a standardized range (10-30 mm) through the fixed geometry of the bonding flange, rather than requiring variable thickening laminates with different thicknesses at different locations.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If core material is used in the transition piece, then the adhesive gap is maintained, but the bonding quality cannot be inspected by ultrasound and shear load resistance is reduced

Engineering Contradiction:
Improveadhesive gap maintenanceVSAvoidbonding quality inspection capability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The invention extracts and eliminates the core material from the transition piece structure. Instead of using core material to maintain the adhesive gap, the design uses a C-shaped bonding flange with inherent geometric features that maintain the gap without requiring non-inspectable core material. This extraction of core material enables full ultrasonic inspection capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the mechanical support function previously provided by core material with a structurally optimized C-shaped bonding flange. The bonding flange maintains the adhesive gap through its geometric design rather than relying on core material, while simultaneously providing adequate mechanical support and enabling inspection.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If the adhesive joint thickness is increased in the transition area, then the gap tolerance is accommodated, but the joint strength decreases and cracking occurs

Engineering Contradiction:
Improvegap tolerance accommodationVSAvoidadhesive joint strength
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The invention changes the parameter of adhesive joint thickness from a variable, uncontrolled dimension to a controlled, standardized dimension through the C-shaped bonding flange. By fixing the geometry of the bonding flange, the adhesive gap is maintained within the optimal 10-30 mm range, preventing both excessive thickness (which would reduce strength) and insufficient thickness (which would not accommodate the gap).

Inventive Principle:
Principle #35Parameter changes

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 maintains a constant adhesive joint thickness, improves structural integrity, and enables reliable inspection of the adhesive bond, reducing the risk of damage and ensuring secure load transfer in the transition area.

Implementation Method 1

the transition piece has, along the main extension direction, a root-side section being formed as a C-shaped bonding flange and a tip-side section being formed as a monolithic wedge

Methodology Applied
Scientific EffectGeometric constraint: Geometry

Implementation Method 2

enables reliable inspection of the adhesive bond

Methodology Applied
Scientific EffectUltrasonic wave propagation: Ultrasound

Data Source

PatentEP4631707A1Method of manufacturing a wind turbine rotor blade, wind turbine rotor blade and transition piece
Publication Date: 2025.10.15 NORDEX ENERGY SE & CO KG
  • EP4631707A1 patent drawingFigure 1
  • EP4631707A1 patent drawingFigure 2~3
  • EP4631707A1 patent drawingFigure 4~5

AI summary

The invention relates to a method of manufacturing a wind turbine rotor blade (110), the wind turbine rotor blade (110) having a first section (148) comprising a blunt trailing edge (142) and being located close to a rotor blade root region (114), a second section (150) comprising a sharp trailing edge (136) and being located in direction towards a rotor blade tip region (152) and a third section (154) being located between the first section (148) and the second section (150), wherein - a transition piece (156) is arranged between two half shells (132) along the trailing edge (136) of the third section (154) firmly connecting both half shells (132), - the transition piece (156) has a root-side end (162) and a tip-side end (164) and extends along a main extension direction (166) from the root-side end (162) to the tip-side end (164), - the transition piece (156) has, along the main extension direction (166), a root-side section (168) being formed as a C-shaped bonding flange and a tip-side section (170) being formed as a monolithic wedge. The invention also concerns a wind turbine rotor blade (110) and a transition piece (156).