Tapered Serrated Spar Cap for Wind Blade Layup Conformability

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Solution Overview

Problem

The manufacturing of spar caps for large wind turbine blades is challenging due to the double curved surface geometry, which causes panel stiffness issues and difficulty in conforming to irregularities and geometry deviations, making it hard to layup fibre layers smoothly.

Innovation Solution

A spar cap design with a tapering thickness and serrated ends, comprising unidirectional reinforcing fibre layers and fibre skin layers, allowing it to conform easily to the fibre reinforcement material in the turbine blade shell mould, regardless of panel stiffness or local irregularities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a prefabricated spar cap is manufactured with a rigid geometry to meet design criteria, then structural strength is improved, but the ability to conform to irregularities and geometry deviations in the blade shell mould deteriorates

Engineering Contradiction:

Improvestructural strengthVSAvoidability to conform to irregularities

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The spar cap is divided into multiple fibre reinforcement layers (first plurality and second plurality) that can be independently arranged and positioned. This segmentation allows each layer to adapt to local geometry deviations while maintaining overall structural integrity, resolving the contradiction between rigidity and conformability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the spar cap are designed with different layer configurations and orientations. The fibre reinforcement layers can be locally adjusted to match specific geometric requirements of the blade shell, allowing the structure to maintain strength while adapting to local irregularities in the mould geometry.

Inventive Principle:

Principle #3Local quality

2Productivity

If the blade shell uses a double curved surface geometry to achieve aerodynamic efficiency, then aerodynamic performance is improved, but the difficulty of laying up fibre layers smoothly deteriorates due to increased panel stiffness

Engineering Contradiction:

Improveaerodynamic efficiencyVSAvoidease of fibre layup

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The fibre reinforcement layers are designed with the ability to dynamically adapt to the double curved surface geometry. By using multiple flexible layers that can be positioned and oriented independently, the system maintains flexibility during manufacturing while achieving the rigid aerodynamic shape required for optimal performance.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The spar cap utilizes composite fibre reinforcement layers that combine flexibility for easy layup with structural rigidity when cured. This composite structure allows the material to conform to complex double curved surfaces during manufacturing while maintaining the structural integrity and aerodynamic precision required for high efficiency.

Inventive Principle:

Principle #40Composite materials

3Ease of manufacture

If the spar cap is manufactured offline as a prefabricated element, then manufacturing flexibility is improved, but the difficulty of making it conform to the layup surface deteriorates due to panel stiffness

Engineering Contradiction:

Improvemanufacturing flexibilityVSAvoidconformity to layup surface

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The offline-manufactured spar cap is segmented into multiple fibre reinforcement layers that can be independently positioned and adjusted. This segmentation enables the prefabricated element to conform precisely to the layup surface geometry while maintaining the manufacturing flexibility benefits of offline production.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The fibre reinforcement layers are designed with adjustable parameters such as layer thickness, orientation, and positioning that can be optimized to match the specific layup surface geometry. This allows the prefabricated spar cap to achieve high conformity precision while retaining the advantages of offline manufacturing flexibility.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12540597B2Spar cap with tapering and serrated end section

Publication Date: 2026.02.03 LM WIND POWER AS

AI summary

The present invention relates to a spar cap for a wind turbine blade and a method for manufacturing said spar cap. The spar cap comprises: a plurality of reinforcing fibre layers comprising unidirectionally oriented reinforcement fibres, wherein the plurality of reinforcing fibre layers are arranged such that the spar cap tapers in thickness towards a first longitudinal end, and a number of first fibre skin layers arranged on a first surface of the plurality of reinforcing fibre layers, and a number of second fibre skin layers arranged on a second surface of the plurality of reinforcing fibre layers, such that the plurality of reinforcing fibre layers are arranged between the number of first fibre skin layers and the number of second fibre skin layers. The number of first fibre skin layers and the number of second fibre skin layers extend beyond the plurality of reinforcing fibre layers towards the first longitudinal end of the spar cap, and the first longitudinal end of the spar cap is serrated along a transverse direction, forming a first serrated section.