Wind Turbine Spar Cap Locating Features for Shear Web Bonding

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Solution Overview

Problem

The existing methods for manufacturing large-scale composite structures, such as wind turbine blades, face challenges in ensuring proper placement and bonding of shear webs during the mold closure process, often resulting in sub-optimal bonding positions and increased weight due to the use of permanent fixtures.

Innovation Solution

The proposed solution involves a spar cap with integrated locating features and a bond gap feature, which guides the shear web into precise position and ensures adequate adhesive application, eliminating the need for external fixtures and simplifying the assembly process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If permanent fixtures are used to guide shear webs during mold closure, then positioning precision is improved, but device complexity and weight increase

Engineering Contradiction:
Improvepositioning precisionVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The locating features are integrated directly into the spar cap structure itself, merging the positioning function with the structural component. This eliminates the need for separate permanent fixtures while maintaining positioning precision during mold closure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The positioning function is extracted from external permanent fixtures and incorporated into the spar cap design. This removes the complexity and weight of separate fixtures while preserving the guiding capability for shear webs.

Inventive Principle:
Principle #2Taking out (Extraction)

2Manufacturing precision

If permanent fixtures are used to guide shear webs during mold closure, then positioning precision is improved, but weight increases

Engineering Contradiction:
Improvepositioning precisionVSAvoidblade weight
Core Design Contradiction:
Manufacturing precisionVSWeight of moving object

Solution Approach 1:

The locating features are merged with the spar cap structure, eliminating the need for additional permanent fixtures. This reduces the overall blade weight while maintaining the positioning precision required for shear web placement during mold closure.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If adhesive is applied without guidance features, then application speed is improved, but bonding precision deteriorates

Engineering Contradiction:
Improveapplication speedVSAvoidbonding precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The bond gap feature acts as an intermediary element that guides adhesive flow between the spar cap and shear web. This ensures precise adhesive placement and adequate bonding without requiring complex application control systems, maintaining both speed and precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of operation

If shear webs are allowed to move during mold closure, then ease of assembly is improved, but bonding precision deteriorates

Engineering Contradiction:
Improveease of assemblyVSAvoidbonding precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The locating features on the spar cap enable the shear webs to self-align and self-position during assembly. The shear webs automatically engage with the locating features, ensuring precise positioning without requiring external fixtures or complex alignment procedures, thus maintaining both ease of assembly and bonding precision.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3849784B1Positioning profiles for pultrusions in wind blade spar caps
Publication Date: 2025.04.30 TPI COMPOSITES INC
  • EP3849784B1 patent drawingFigure 1A
  • EP3849784B1 patent drawingFigure 1B
  • EP3849784B1 patent drawingFigure 1C

AI summary

Provided herein is a spar cap having a profile for guiding and receiving a shear web for wind turbine blade. Particularly, the present disclosure provides a pultruded spar cap having a bond gap feature to maintain a uniform space for distribution of bonding paste between the spar cap and shear web. Also, the spar cap is formed with locating features which guide and receive placement of the shear web.