Variable Thickness Wind Turbine Tower Attachment Element
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Solution Overview
Problem
Existing methods for attaching add-on parts to wind turbine towers using weld-in sleeves result in a weakened tower wall, leading to reduced stability and the need for thicker tower designs to meet notch class requirements, which increases material and installation costs.
Innovation Solution
A device with an add-on element that has a reduced material thickness at one end face compared to the other, providing flexibility to absorb peak loads and prevent their introduction into the welded connection, allowing for a higher notch class classification and thinner tower designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If weld-in sleeves are used to attach add-on parts to the tower wall, then the attachment function is achieved, but the tower wall is weakened and stability is reduced
Solution Approach 1:
The add-on element features variable wall thickness with a thinner first wall portion at the weld connection area and a thicker second wall portion at the attachment area. This local quality variation allows the connection point to have lower stiffness (absorbing peak loads) while maintaining overall structural integrity and stability.
Solution Approach 2:
The invention changes the geometric parameter of the add-on element by varying its wall thickness along the length. The first wall portion has a first thickness while the second wall portion has a second thickness greater than the first, creating a gradient structure that modifies load distribution and prevents peak load transmission to the tower wall.
2Stability of the object's composition
If the tower wall is designed with greater thickness to compensate for connection weakening, then stability is improved, but material costs and weight increase
Solution Approach 1:
Instead of uniformly thickening the entire tower wall, the invention applies local quality optimization at the connection point by using an add-on element with variable thickness. This localized solution maintains stability where needed while avoiding unnecessary weight increase throughout the entire tower structure.
Solution Approach 2:
The add-on element with variable wall thickness acts as a pre-designed cushioning element that absorbs peak loads before they can be transmitted to the tower wall. The thinner first wall portion is intentionally designed to yield first, protecting the tower wall from high stress concentrations.
3Reliability
If the add-on element has variable wall thickness, then peak loads are absorbed and notch class is improved, but manufacturing complexity increases
Solution Approach 1:
The variable wall thickness design applies local quality differentiation only where needed - the first wall portion is thinner at the weld connection zone while the second wall portion is thicker at the attachment zone. This targeted approach improves notch class without requiring complex structures throughout the entire element.
Solution Approach 2:
The add-on element features asymmetric wall thickness distribution along its length, with the first wall portion having a different thickness than the second wall portion. This asymmetric design creates the desired flexibility gradient to absorb peak loads while maintaining structural integrity, representing a controlled form of complexity.
Data Source
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AI summary
In order to provide an attachment element for fastening of attachment parts (P) to a metal inner tower wall (T) of a tower of a wind energy system, comprising a first end side for welding to the inner tower wall (T) and a second end side for fastening an attachment part (P), said second side opposite the first end side, wherein the resultant weld connection between said attachment element and the tower wall is under a reduced stress, thereby enabling the connection point to be assigned to a higher fatigue class, it is proposed that such an attachment part have a total cross-sectional material thickness that is reduced near the first end side in comparison to a total material thickness in a cross-section shifted toward the second end side.