Jointed Wind Turbine Blade Spar Cap Bonding
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Solution Overview
Problem
The jointed wind turbine rotor blade configuration faces challenges in ensuring structural integrity at the bonded joint without adding unnecessary weight, particularly as wind turbines increase in size and complexity.
Innovation Solution
A modified spar cap configuration with varying chord-wise widths and thicknesses in the second blade segment provides a larger bonding surface area and reduced thickness for increased structural integrity, using either continuous or different materials with a scarf joint, and a transition section to maintain structural properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a jointed blade configuration is used to enable larger wind turbine blades, then the blade size and power generation efficiency are improved, but the structural integrity at the bonded joint is compromised
Solution Approach 1:
The spar cap is designed with varying thickness along its span: thicker at the root end and thinner at the tip end. This local variation in geometry provides enhanced bonding surface area and structural strength precisely where the joint is located, while maintaining overall blade轻量化. The local quality principle resolves the contradiction by concentrating structural reinforcement only where needed (at the joint) rather than uniformly throughout the entire blade.
Solution Approach 2:
The blade is divided into multiple segments that are joined together to form a complete blade. The jointed configuration allows the blade to be manufactured in sections and assembled, enabling larger blade lengths that would be impossible to manufacture and transport as single pieces. The segmentation principle directly enables the improvement in blade length while the bonding design ensures structural integrity at the joints.
2Reliability
If additional structural reinforcement is added at the bonded joint to improve structural integrity, then the reliability is improved, but the blade weight increases
Solution Approach 1:
The spar cap thickness is varied locally along the blade span, being thicker only at the joint region and thinner elsewhere. This localized reinforcement provides the necessary bonding surface area and structural strength at the joint without adding weight to the entire blade. The principle resolves the contradiction by applying material only where structurally necessary.
Solution Approach 2:
The spar cap provides more bonding surface area than would be present in a uniform thickness design, creating an 'excessive' local feature that specifically addresses the joint integrity requirement. This partial reinforcement (only at the joint area) achieves the reliability improvement without the penalty of uniform reinforcement throughout the entire blade structure.
Data Source
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AI summary
A jointed wind turbine rotor blade includes a first blade segment and a second blade segment extending in opposite directions from a chord-wise joint line. Each of the first and second blade segments includes opposite spar caps. The first and second blade segments are connected at the chord-wise joint line by internal joint structure, wherein the joint structure is bonded to the opposite spar caps in at least the second blade segment. The spar caps in the second blade segment have a first section with a first chord-wise width that is unbonded to the joint structure and a second section with a second chord-wise width that is bonded to the joint structure. The second chord-wise width is greater than the first chord-wise width.