Wind Turbine Blade Recess Inserts for Resin Impregnation
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Solution Overview
Problem
The manufacturing of wind turbine blades faces challenges in ensuring complete impregnation of fibre materials with resin during the vacuum infusion process, leading to dry spots and increased curing time, especially for large blades, which complicates the control of flow fronts and results in potential deformations and local weakening of the structure.
Innovation Solution
A method involving the use of inserts with an exterior shape corresponding to the recess in the aerodynamic shell part, allowing for accurate formation of the recess and connection of spar caps, along with a kit of parts including a mould and inserts to ensure precise positioning and prevent fibre material slippage, utilizing vacuum-assisted resin transfer moulding to cure the resin before removing the inserts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If vacuum infusion is used to manufacture large blade shells, then the aerodynamic shape can be controlled accurately, but dry spots occur and complete impregnation becomes difficult to ensure
Solution Approach 1:
The invention divides the fibre reinforcement material into multiple separate layers rather than using a single thick layer. This segmentation allows resin to penetrate through each layer more effectively, preventing dry spots while maintaining the aerodynamic shape control achieved through vacuum infusion moulding
Solution Approach 2:
The fibre reinforcement layers are pre-aligned and positioned in the mould before resin injection. This preliminary arrangement ensures optimal resin flow paths and prevents misalignment during the infusion process, thereby ensuring complete impregnation while maintaining manufacturing precision
2Reliability
If staff puncture the vacuum bag to repair dry spots, then dry spots can be addressed, but the process is time-consuming and may cause deformations
Solution Approach 1:
The fibre reinforcement layers are pre-aligned and secured in the mould before resin injection begins. This preliminary positioning prevents fibre displacement during the infusion process, eliminating the need for time-consuming repairs and avoiding deformations that would require corrective intervention
Solution Approach 2:
The invention introduces a restraining structure or system that holds the fibre reinforcement layers in place during resin infusion. This intermediary element prevents fibre movement without requiring manual intervention, thereby reducing repair time and preventing deformations
3Object-generated harmful factors
If overpressure is applied at the inlet side to remove air pockets, then air removal is attempted, but dry spots remain difficult or impossible to eliminate
Solution Approach 1:
By dividing the fibre reinforcement into multiple thinner layers, the invention creates more resin flow paths and reduces the distance resin must travel to reach all fibre surfaces. This segmentation eliminates air pockets more effectively than single-layer construction, as resin can penetrate and displace air more efficiently through the distributed layer structure
Solution Approach 2:
The invention changes the structural parameters of the fibre reinforcement system by using multiple layers with specific thickness and spacing. This parameter modification optimizes resin flow characteristics and pressure distribution, enabling complete air pocket removal and eliminating dry spots that persist under conventional single-layer conditions
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 method simplifies the formation of the aerodynamic shell with a recess, ensures accurate positioning of the spar cap, and reduces the risk of deformations by maintaining fibre and core material alignment, thereby improving the manufacturing efficiency and mechanical properties of the wind turbine blade.
Implementation Method 1
a vacuum, said vacuum in this connection being understood as an under-pressure or negative pressure, is generated via vacuum outlets in the mould cavity, whereby liquid polymer is drawn into the mould cavity via the inlet channels
Data Source
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AI summary
A method of manufacturing an aerodynamic shell part for a wind turbine blade is described. The aerodynamic shell part comprises a recess for arrangement and connection of a spar cap within said recess. The method comprising the steps of: a) providing a first mould part having a first forming surface that defines a part of an exterior of the aerodynamic shell part, b) laying up fibre-reinforcement material and optionally also sandwich core material in the first mould on the first forming surface, c) arranging one or more inserts having an exterior shape corresponding to at least sides of the recess of the aerodynamic shell part, d) supplying resin to said fibre-reinforcement material and optional sandwich core material, e) curing or preconsolidating the resin, and f) removing the one or more inserts.