Trailing-Edge Spar Cap Fiber Layout for Consistent Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The integration of spar caps in wind turbine rotor blades is challenging due to the limited space near the trailing edge, requiring improved design for stiffness and bonding, especially in regions with varying thickness and shape.
Innovation Solution
A spar cap design using a stack of fiber layers with different types, where first-type layers are offset and second-type layers are flush, forming a trapezoidal and quadrangular cross-sections, allowing efficient placement along the trailing edge and optimizing the bonding gap for a homogeneous adhesive joint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If spar cap thickness is increased to provide required stiffness in the trailing edge region, then structural stiffness is improved, but the available space near the trailing edge is exceeded making integration difficult
Solution Approach 1:
The spar cap is divided into multiple fiber layers with different types (first-type and second-type layers). Each layer type serves specific structural functions, allowing the spar cap to achieve required stiffness through optimized layer configuration rather than simply increasing overall thickness.
Solution Approach 2:
Different fiber layers are positioned at specific locations within the spar cap structure. The first-type and second-type fiber layers are arranged at different heights and positions to provide localized stiffness where needed, rather than uniformly increasing thickness throughout the entire spar cap.
2Strength
If fiber layers are arranged to maximize structural efficiency, then mechanical properties are improved, but manufacturing complexity increases
Solution Approach 1:
The fiber layers are segmented into first-type and second-type layers that can be manufactured and positioned separately. This segmentation allows for standardized manufacturing processes for each layer type while achieving complex overall structural properties through their combination.
Solution Approach 2:
The spar cap utilizes a composite structure combining first-type and second-type fiber layers. This composite approach allows each layer type to be optimized for specific manufacturing processes while the combined structure achieves superior mechanical properties.
3Adaptability or versatility
If bonding gap thickness varies significantly in the trailing edge region, then adaptation to varying blade geometry is improved, but adhesive joint quality deteriorates
Solution Approach 1:
The fiber layers are positioned at specific heights and locations to create a bonding gap structure that adapts to varying blade geometry while maintaining consistent adhesive joint quality. Different layer positions compensate for geometric variations locally.
Solution Approach 2:
The solution addresses bonding gap consistency by utilizing the vertical dimension (layer height positioning) rather than attempting to control horizontal gap variations. By positioning fiber layers at different heights, the design compensates for geometric variations and maintains consistent adhesive thickness.
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 design enhances structural efficiency, facilitates easy integration into the rotor blade, and improves the quality and mechanical properties of the adhesive joint by maintaining a consistent bonding thickness.
Implementation Method 1
The stack is resin-infused and cured, to form the spar cap
Data Source
Figure 1
Figure 2~3
Figure 4~6
AI summary
The invention relates to a spar cap (136) for a wind turbine rotor blade (110), the spar cap (136) being configured to extend close to a trailing edge (135) and to form, at least in a section between a root end (126) and a tip end (144), a part of the trailing edge (135) of the wind turbine rotor blade (110), the spar cap (136) comprising a stack (146) of fiber layers including first-type fiber layers (148) and second-type fiber layers (150), wherein - a layer width (154) of the first-type fiber layers (148) is smaller than a layer width (156) of the second-type fiber layers (150), - in the stack (146), the first-type fiber layers (148) are arranged offset to each other with respect to a width (W) of the stack (146), and - in the stack (146), the second-type fiber layers (150) are aligned flush with one another with respect to the width (W) of the stack (146), - the stack (146) is resin-infused and cured. The invention also concerns a wind turbine rotor blade (110) and a method of manufacturing a spar cap.