Wind Turbine Rotor Blade Spar Joint for Section Load Transfer
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Solution Overview
Problem
Existing connections between rotor blade sections of wind turbines face challenges in efficiently distributing tensile and compressive stresses as rotor blade lengths increase, particularly in cross-sectioned blades, necessitating improved structural integrity and manufacturing efficiency.
Innovation Solution
The connection between rotor blade sections incorporates widened flange sections of the spar, which serve as carriers for connecting elements, with these elements being positively anchored in undercut recesses, and optionally using pin or laminate connecting elements to ensure structural stability and compatibility with fiber composite materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If rotor blades are divided into sections for transport and manufacturing advantages, then ease of manufacture and transport are improved, but structural integrity and load distribution are worsened
Solution Approach 1:
The rotor blade is divided into multiple sections that can be manufactured and transported separately, then connected through the spar belt parts. This segmentation enables manufacturing efficiency and transport advantages while maintaining structural integrity through the connection design.
Solution Approach 2:
The belt parts of the spars from opposite rotor blade sections are merged by widening them to form opposing abutment surfaces that are connected together. This merging creates a continuous load-bearing structure that restores structural integrity across the joint.
2Ease of operation
If rotor blade sections are connected using conventional methods, then assembly is simplified, but load distribution and tensile resistance are worsened
Solution Approach 1:
The belt parts are widened in the transverse dimension to create extensive abutment surfaces. This dimensional change provides large-area contact for load distribution while maintaining straightforward assembly through the expanded connection interface.
Solution Approach 2:
Connecting elements are introduced as intermediary components that transfer loads between the widened belt parts of opposite sections. These intermediaries distribute tensile and shear loads across the connection area while simplifying the assembly process.
3Strength
If the spar belt parts are widened to form abutment surfaces, then load distribution is improved, but device complexity increases
Solution Approach 1:
The widened belt parts serve multiple functions: they provide structural strength, create abutment surfaces for load distribution, and form interfaces for connecting elements. This multi-functionality reduces the need for additional specialized components, thereby limiting complexity increase.
Solution Approach 2:
The belt parts are widened specifically in the connection area where load distribution is critical, while maintaining standard dimensions elsewhere. This localized modification optimizes tensile and shear resistance at the joint without unnecessarily increasing overall device complexity.
Data Source
Figure 1(a)~3
Figure 4~7
Figure 8(a)~9
AI summary
The invention relates to a connection between sections (2,3) of a rotor blade (1) of a wind turbine rotor divided transversely to its longitudinal axis, wherein the rotor blade (1) has a hollow airfoil profile with a low-pressure side wall shell (5) and a high-pressure side wall shell (6) and a spar (7) extending in the cavity between the wall shells (5,6) in the longitudinal direction of the blade, which is connected to the wall shells (5,6) via belt parts (8,9) of the spar (7).The connection according to the invention is characterized in that the belt parts (8,9) of the spar (7) of the rotor blade sections (2,3) are widened in a connection area (4) to form opposing impact surfaces (11, 12), that recesses (13) for receiving connecting elements (14) projecting from the opposite impact surface open in at least one of the impact surfaces (11,12), and that the connecting elements (14) are anchored in the receiving recesses (13) in a materially bonded manner.