Wind Turbine Rotor Blade Shear Web with Compressed Flanges
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Solution Overview
Problem
Conventional shear webs in wind turbine rotor blades face challenges in achieving precise length dimensions and adequate bonding between spar caps and shear webs, leading to time-consuming processes and minimal bonding surfaces, while also adding weight due to the use of reinforced laminate composite materials.
Innovation Solution
The implementation of a shear web design featuring first and second outer pultruded layers with compressed flanges at opposing ends, which are bonded to upper and lower spar caps, and optionally include a core material, allowing for easier assembly and increased stiffness and strength, using methods such as 3D pultrusion and various bonding techniques like thermoplastic welding or adhesives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional reinforced laminate composite materials are used for shear webs, then the desired strength and stiffness are achieved, but the weight of the wind turbine increases
Solution Approach 1:
The patent employs a composite structure consisting of a foam core material surrounded by pultruded fiber-reinforced polymer layers. This composite design provides the necessary strength and stiffness while maintaining lower weight compared to solid reinforced laminate composites. The foam core offers structural support with minimal weight penalty, and the pultruded layers provide the required mechanical strength.
2Strength
If conventional shear web construction methods are used, then the shear web provides structural support, but the manufacturing process is time-consuming and requires significant rework due to difficulty in achieving precise length dimensions and adequate bonding
Solution Approach 1:
The shear web is pre-assembled with the spar caps in a controlled environment before installation in the rotor blade. This preliminary assembly allows for precise adjustment of length dimensions and bonding surfaces, ensuring adequate bonding without requiring time-consuming rework during final installation. The pre-assembly process enables verification and correction of dimensional accuracy before the component is integrated into the complete blade structure.
Solution Approach 2:
The patent modifies the bonding parameters by using extended bonding surfaces on the shear web that interface with the spar caps. This design change increases the bonding area and improves the quality of the bond, while the pultrusion process enables precise control of the shear web dimensions to achieve the required length accuracy without requiring extensive rework.
3Area of stationary object
If conventional shear web design is used, then the shear web spans between spar caps, but the bonding surface between spar caps and shear web is minimal
Solution Approach 1:
The shear web is designed with segmented bonding surfaces that extend along the length of the spar caps. Instead of a single concentrated bonding area, the bonding surface is distributed across multiple locations, increasing the total bonding area and improving the overall bond strength. This segmentation also allows for more uniform stress distribution across the bond line.
Solution Approach 2:
The bonding interface is extended in the longitudinal dimension by designing the shear web to overlap with the spar caps over an extended length. This dimensional extension transforms a point-like or small-area bond into a distributed bond along the length of the structure, significantly increasing the bonding surface area and consequently the bond strength.
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 design enables quicker and more efficient manufacturing of rotor blades with improved bonding surfaces, reducing rework and weight, while providing additional strength and stiffness, and can accommodate features like channels for lightning protection systems.
Implementation Method 1
end portions of the first and second outer pultruded layers form compressed flanges at opposing ends of the shear web that are bonded to the upper and lower spar caps
Implementation Method 2
compressed flanges at opposing ends of the shear web that are bonded to the upper and lower spar caps
Implementation Method 3
first and second outer pultruded layers
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The present disclosure is directed to a shear web for a rotor blade of a wind turbine and a method of manufacturing and assembling same. The rotor blade generally includes an upper shell member having an upper spar cap configured on an internal surface thereof and a lower shell member having a lower spar cap configured on an internal surface thereof. Further, the shear web extends between the spar caps along a longitudinal length of the blade. In addition, the shear web includes first and second outer pultruded layers at least partially encompassing a core material, wherein end portions of the first and second outer pultruded layers form compressed flanges at opposing ends of the shear web.