Wind Turbine Mandrel with Compressible Outer Layer for Hollow Composite Blades
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional mandrels used in producing hollow composite structures for wind turbine rotor blades face challenges such as bridging, which results in resin build-up, increased weight, and risk of cracking, due to their susceptibility to compressibility and inability to maintain precise shape definitions, especially at internal corners with smaller radii.
Innovation Solution
A mandrel design comprising a core of a first compressible material, an outer layer of a second more compressible material arranged radially outward, and a first intensifier member that intensifies pressure on the inner areas of the lay-up, allowing for a defined shape corresponding to the desired inner shape of the hollow composite component to be achieved.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional mandrel is used to produce hollow composite structures, then the manufacturing process is simple, but bridging occurs resulting in resin build-up, increased weight, and risk of cracking
Solution Approach 1:
The mandrel employs different materials with varying compressibility properties in different regions. The core uses a first compressible material while the outer layer uses a second, more compressible material, creating local quality variations that prevent bridging at critical areas like internal corners while maintaining overall structural integrity
Solution Approach 2:
The mandrel is constructed as a composite structure combining a core of first compressible material with an outer layer of second compressible material that is more compressible than the core. This composite material approach allows each layer to perform its specific function in preventing bridging and maintaining shape definition
2Ease of operation
If a compressible mandrel is used, then the mandrel can be extracted through the opening after curing, but the mandrel cannot maintain precise shape definitions at internal corners with smaller radii
Solution Approach 1:
The mandrel design applies different compressibility characteristics to different regions: the core provides structural support while the more compressible outer layer specifically addresses areas needing precision definition, such as internal corners, by providing targeted pressure distribution during curing
Solution Approach 2:
The mandrel is segmented into distinct functional layers - a core providing basic shape maintenance and an outer layer providing enhanced compressibility for extraction. This segmentation allows each layer to be optimized for its specific purpose while working together to achieve both precision and extractability
3Strength
If resin build-up occurs due to bridging, then the composite structure gains strength locally, but weight increases and cracking risk increases
Solution Approach 1:
The mandrel's differentiated compressible material structure proactively prevents bridging before it can occur during the curing process. By designing the outer layer to be more compressible than the core, the mandrel creates appropriate pressure distribution that eliminates the conditions for bridging and resin build-up, thereby preventing the harmful effects before they manifest
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 improved mandrel design effectively reduces bridging and resin build-up, achieving a better-defined shape of the hollow composite component, thereby minimizing weight and thermal degradation issues, and enhancing the overall quality and reliability of the wind turbine rotor blade components.
Implementation Method 1
a first intensifier member for intensifying a pressure on a first inner area of a lay-up
Implementation Method 2
a second material being more compressible than the first material
Implementation Method 3
a vacuum is drawn on the mandrel to compress the compressible material
Data Source
Figure 1
Figure 2A~2B
Figure 3~4
AI summary
It is provided a mandrel for producing a hollow composite component of a wind turbine rotor blade, the mandrel comprising a core (110) of a first material; an outer layer (120) of a second material arranged radially outward of the core, the second material being more compressible than the first material; and a first intensifier member (130) for intensifying a pressure on a first inner area of a lay-up, the first intensifier member being arranged at least partially radially outward of the core, wherein a first outer surface (135) of the first intensifier (130) member and a second outer surface (125) of the outer layer (120), together, forms a defined shape corresponding to a desired inner shape of at least a portion of the hollow composite component.