Winged Spar Cap Structure for Stronger Jointed Wind Blades
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Solution Overview
Problem
Wind turbine rotor blades face structural integrity challenges at bonded joints, particularly in jointed configurations, without adding unnecessary weight or compromising structural integrity in other parts of the blade.
Innovation Solution
A modified spar cap configuration for jointed wind turbine blades, featuring opposite spar caps with a center section of high rigidity and wing members of lower rigidity, flared to accommodate a receiver box, ensuring structural integrity while minimizing weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the spar cap is made uniformly thick and rigid throughout, then structural strength is maximized, but weight increases unnecessarily
Solution Approach 1:
The spar cap employs varying thickness along its longitudinal axis, with a first thickness in a first region and a second, greater thickness in a second region. This local quality variation provides enhanced structural strength at the second region where higher strength is needed, while maintaining lighter weight in the first region, thus resolving the contradiction between uniform strength and weight reduction.
2Strength
If the spar cap thickness is increased to improve structural integrity at bonded joints, then joint strength is improved, but the blade becomes more difficult to transport and assemble
Solution Approach 1:
The spar cap is segmented into different regions with different thickness characteristics. The first region has a first thickness suitable for standard manufacturing and transport, while the second region has a greater thickness providing enhanced joint strength. This segmentation allows the blade to be manufactured and transported more easily while still achieving the required structural integrity at bonded joints.
3Strength
If multiple bolt joints are used to connect beam structure with receiving section, then connection strength is improved, but device complexity increases
Solution Approach 1:
The spar cap's varying thickness creates a second region with greater thickness that provides enhanced structural support and strength at the bonded joint without requiring multiple bolt joints. This local quality improvement allows for a simpler joint structure with fewer fasteners, thus reducing device complexity while maintaining connection strength.
Data Source
Figure 1
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AI summary
A wind turbine rotor blade includes a first blade segment and a second blade segment extending in opposite directions from a chord-wise joint line and connected at the chord-wise joint line by internal joint structure. Opposite spar caps in the first blade segment include a longitudinally extending center section having a constant transverse width up to the chord-wise joint line. Wing members are disposed against opposite longitudinal sides of the center section, each wing member having a head section with a constant transverse width and a flared tail section having a decreasing transverse width, the head section aligned with an end of the center section at the chord-wise joint line. The center section is formed from a first material having a first rigidity and the wing members are formed at least partially from a second material having a second lesser rigidity such that the wings members have an overall rigidity that is less than first rigidity of the center section.