Flatback Blade Shell Corner Core for Reliable Trailing-Edge Bonding

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Solution Overview

Problem

Manufacturing wind turbine blades with a flatback trailing edge is challenging due to difficulties in bonding the pressure and suction side shell halves, especially when traditional cores cannot provide sharp corners, leading to slip and manufacturing issues in large structures.

Innovation Solution

A blade shell section design with a corner core element that accommodates the complex geometry of flatback wind turbine blades, featuring a corner core element with varying radii of curvature and abutting lateral faces to ensure secure bonding and reduced wrinkle formation during laminate layup, using lightweight materials like expanded polymer foam or balsa wood.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional cores (balsa wood or foamed polymer) are used, then manufacturing is simpler, but sharp corners cannot be provided and corners slip relative to the core

Engineering Contradiction:
Improvesharp corner geometryVSAvoidmanufacturing complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The core structure is divided into a main core body and separate corner elements. The corner elements are pre-formed with sharp corner geometries and then attached to the main core body, allowing the sharp corners to be provided without requiring the entire core to be complex to manufacture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Corner elements act as intermediary components between the main core body and the blade shell. These corner elements provide the sharp corner geometry needed for precise bonding interfaces while being separately manufacturable and attachable to the main core.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If flatback trailing edge geometry is implemented, then energy production improves, but bonding between pressure and suction side shell halves becomes difficult

Engineering Contradiction:
Improveenergy productionVSAvoidbonding reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

Corner elements with precise geometries are prepared in advance and positioned at the trailing edge corners before the bonding process. This preliminary positioning ensures that the bonding interfaces between pressure and suction side shell halves are properly aligned and maintained during the bonding operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The corner elements have varying radii of curvature along their length, with different radii at different positions. This parameter variation allows the corner elements to accommodate the complex flatback geometry while providing stable bonding surfaces for the shell halves.

Inventive Principle:
Principle #35Parameter changes

3Shape

If separate loose corner elements are used to provide sharp corners, then corner geometry is improved, but elements slip relative to the core and are not maintained in intended position

Engineering Contradiction:
Improvecorner sharpnessVSAvoidposition stability
Core Design Contradiction:
ShapeVSStability of the object's composition

Solution Approach 1:

The corner elements are merged with the main core body through attachment mechanisms (such as adhesives or mechanical fasteners). This merging ensures that the corner elements remain firmly positioned relative to the core while maintaining their sharp corner geometries.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The corner elements are positioned within recesses or cavities in the main core body, creating a nested arrangement. This nesting provides mechanical retention and prevents the corner elements from slipping relative to the core while allowing them to maintain their sharp corner shapes.

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP4150205B1Blade shell section and a wind turbine blade comprising a blade shell section
Publication Date: 2026.03.25 LM WIND POWER AS
  • EP4150205B1 patent drawingFigure 1
  • EP4150205B1 patent drawingFigure 2
  • EP4150205B1 patent drawingFigure 3~4

AI summary

Disclosed is a blade shell section of a wind turbine blade, such as wind turbine blade with a flatback section. The blade shell section extends in a longitudinal direction from a first shell section position to a second shell section position. The blade shell section comprises a first laminate layer forming the outer surface of the blade shell section and a second laminate layer forming the inner surface of the blade shell section. The blade shell section further comprising a first shell section and a corner shell section between the contour shell section and the flatback shell section.