Flow Formed Steel Connection Element for Wind Turbine Towers

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Solution Overview

Problem

Existing methods for producing connecting elements in steel constructions, such as those for wind turbines, face issues like low fatigue strength due to weld seams, high assembly and logistics costs, material inhomogeneities, and limited weldability, particularly in complex structures like towers and tension pylons.

Innovation Solution

A method using a flow-forming process to produce connecting elements with a flange and integrally attached jacket from a blank, allowing for adjustable end contours and reduced weld seams, increased material thickness, and improved force distribution, enabling easy assembly and strong, adjustable connections without the need for extensive welding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If welded structures consisting of individual sheets are used to produce connecting elements, then assembly flexibility is improved, but fatigue strength deteriorates due to weld seams creating metallurgical notches

Engineering Contradiction:

Improveassembly flexibilityVSAvoidfatigue strength

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The patent merges multiple individual sheet components into a single integral connecting element produced by flow forming. This eliminates the need for weld seams between multiple parts, thereby resolving the fatigue strength issue while maintaining assembly flexibility through the monolithic structure design.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The flow forming process changes the material parameters by introducing compressive residual stresses during manufacturing. This parameter change improves fatigue strength by counteracting tensile stresses that would otherwise initiate crack propagation at weld seams, while the process itself enables the integral structure needed for assembly flexibility.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If multiple individual parts are used to construct connecting elements, then adaptability is improved, but device complexity increases leading to accumulation of welds and significant assembly effort

Engineering Contradiction:

ImproveadaptabilityVSAvoidnumber of parts

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple individual parts into a single integral connecting element manufactured through flow forming. This reduces device complexity by eliminating the need for multiple components and their associated welds, while adaptability is maintained through the ability to customize the integral element's geometry and features for different applications.

Inventive Principle:

Principle #5Merging (Combining)

3Shape

If castings are used to manufacture connecting elements, then production of complex shapes is improved, but manufacturing cost and material quality deteriorate due to inhomogeneities and voids

Engineering Contradiction:

Improvecomplex shape capabilityVSAvoidmanufacturing cost

Core Design Contradiction:

ShapeVSEase of manufacture

Solution Approach 1:

The patent replaces the casting process with a flow forming process. This substitution eliminates the formation of casting defects such as inhomogeneities and voids, thereby improving material quality. The flow forming process can still produce complex shapes through controlled material flow and forming tool design, while reducing manufacturing costs associated with casting complexity and subsequent inspection/repair.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Productivity

If castings are used to manufacture connecting elements, then production capability is improved, but reliability deteriorates due to limited or no weldability for repair welding

Engineering Contradiction:

Improveproduction capabilityVSAvoidweldability for repair

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent replaces casting with flow forming to produce connecting elements with superior material properties. The flow formed structure maintains production capability while significantly improving reliability by ensuring consistent material quality and weldability throughout the component, eliminating the repair welding limitations inherent in cast structures.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

The method results in connecting elements with enhanced fatigue strength, reduced part count, lower production costs, and improved force flow, allowing for flexible positioning and strong, stable connections in steel constructions.

Implementation Method 1

a flange (12) and a shell (14) which are integrally connected to the flange (12) are produced from a blank (40) by means of a flow forming process

Methodology Applied

Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP3049199B1Method for producing a connection element, and connection element

Publication Date: 2019.11.06 THYSSENKRUPP STEEL EUROPE AG PATENTE PATENT DEPARTMENT

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AI summary

The invention relates to a method for producing a connection element, in particular for steel structures of towers, preferably for wind turbines and to a connection element or node element, wherein a flange (12) and a shell (14) integrally adjoining the flange (12) is produced from a blank (40) by means of a flow forming process, and then the end of the shell (14) opposite the flange (12) is adapted to the contour of the component to which the shell (14) is to be connected. The invention further relates to a connection and node element.