Wind Turbine Rotor Blade Web Recess Manufacturing

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Solution Overview

Problem

The existing methods for manufacturing wind turbine rotor blades require machining a recess into the web, resulting in significant manpower and material waste, as well as potential stress concentrations due to abrupt geometry changes.

Innovation Solution

The method involves arranging a core member with a pre-machined parabolic or semicircular recess within the mold, which is then covered by fiber material layers, eliminating the need for post-curing machining and ensuring smooth load transfer by tapering web tips towards the blade root.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If the recess is machined into the cured web, then the web geometry can be adjusted, but substantial manpower and material waste are required

Engineering Contradiction:
Improveweb geometryVSAvoidweb material waste
Core Design Contradiction:
ShapeVSLoss of substance

Solution Approach 1:

The recess geometry is predetermined in the core member before the web is manufactured. The core member is designed with the recess shape already incorporated, so when fiber material is laid up against it, the web automatically acquires the desired recess geometry without requiring post-curing machining operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The recess geometry is copied from the core member to the web through the fiber material layup process. The fiber material conforms to the core member's recess shape, creating an accurate geometric copy without material removal.

Inventive Principle:
Principle #26Copying

2Shape

If the recess is machined into the cured web, then the web geometry can be adjusted, but substantial manpower is required

Engineering Contradiction:
Improveweb geometryVSAvoidmanufacturing efficiency
Core Design Contradiction:
ShapeVSProductivity

Solution Approach 1:

The recess geometry is predetermined in the core member before the web is manufactured. The core member is designed with the recess shape already incorporated, so when fiber material is laid up against it, the web automatically acquires the desired recess geometry without requiring post-curing machining operations.

Inventive Principle:
Principle #10Preliminary action

3Shape

If the recess is machined into the cured web, then the web geometry can be adjusted, but stress concentrations occur due to abrupt geometry changes

Engineering Contradiction:
Improveweb geometryVSAvoidstress distribution
Core Design Contradiction:
ShapeVSReliability

Solution Approach 1:

The recess features smooth curved transitions with specific radius values (e.g., R10, R20) at critical locations where geometry changes occur. This local optimization of the recess shape ensures smooth stress flow paths and avoids abrupt transitions that would create stress concentrations.

Inventive Principle:
Principle #3Local quality

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 approach reduces manpower and waste by integrating the recess into the core member, allowing for efficient resin impregnation and curing without additional machining, while enhancing load transfer and reducing stress concentrations.

Implementation Method 1

curing a resin impregnating the fiber material of the first and second layup to form the rotor blade

Methodology Applied
Scientific EffectImpregnation: Absorption (physical)

Implementation Method 2

vacuum applied from beneath. Then, mold cores are covered in vacuum bags

Methodology Applied
Scientific EffectVacuum: Vacuum

Data Source

PatentEP2918399B1A method for manufacturing a rotor blade for a wind turbine
Publication Date: 2021.04.28 SIEMENS GAMESA RENEWABLE ENERGY AS
  • EP2918399B1 patent drawingFigure 1
  • EP2918399B1 patent drawingFigure 2~3
  • EP2918399B1 patent drawingFigure 4~5

AI summary

A method for manufacturing a rotor blade (5) for a wind turbine is provided. The method comprises: a) arranging a first layup (39) of fiber material inside a mold (40), the first layup (39) corresponding to an airfoil (7) of the rotor blade, b) arranging a second layup (34) of fiber material on a core member (17) before and/or after arranging the core member (17) in the mold (40), the second layup (34) including the core member (17) corresponding to a web (9) of the rotor blade, the core member (17) comprising a recess (22) configured to ensure a smooth transfer of loads into and out of the web (9), and c) curing a resin impregnating the fiber material of the first (39) and second layup (34) to form the rotor blade (5). The method is advantageous in that there is no need anymore to machine the recess into the cured web, thus saving man power and avoiding waste.