Wind Turbine Tower Segment Fastening Unit
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Solution Overview
Problem
The existing methods for erecting wind turbine towers with prestressed concrete segments are expensive and complicated due to the complex process of fastening the upper end of the tensioning strands.
Innovation Solution
A method involving a fastening unit with a multi-part wedge and pull tab system is used to simplify the assembly of prestressing strands, where the pull tab is attached to the tendons, allowing for upward tensioning and external bracing of tower segments, preventing accidental loosening with a spring-loaded sleeve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional methods are used to fasten the upper end of tensioning strands, then the tower structure is stabilized, but the assembly process becomes expensive and complicated
Solution Approach 1:
The fastening device is divided into multiple functional segments: a clamping element with gripping jaws for securing the tendon, a wedge element for applying clamping force, and a pull tab for operational control. This segmentation allows each component to perform its specific function independently, simplifying the overall assembly process while maintaining reliable tower stabilization.
Solution Approach 2:
The wedge element acts as an intermediary mechanism between the pull tab and the clamping element. When the pull tab is actuated, the wedge translates this motion into radial clamping force on the tendon, providing a simple mechanical transmission that avoids complex fastening mechanisms while ensuring reliable attachment.
2Reliability
If complex fastening mechanisms are used for tensioning strands, then the prestressing is reliable, but the assembly time and cost increase
Solution Approach 1:
The fastening device is designed to be self-actuating through the wedge mechanism. When the pull tab is pulled, the wedge automatically generates the necessary clamping force without requiring external hydraulic or mechanical systems. This self-service approach reduces assembly time and cost while maintaining reliable prestressing through the mechanical advantage provided by the wedge geometry.
Solution Approach 2:
The fastening mechanism transitions from a static attached state to a dynamic actuated state. The pull tab provides a simple dynamic input that triggers the wedge to generate the required clamping force. This dynamic mechanism is much faster and simpler to assemble than traditional static fastening systems, reducing assembly time while ensuring reliable prestressing through the mechanical action.
3Ease of operation
If manual fastening of tendons is used, then the process is simple, but the tensioning force and bracing effectiveness are reduced
Solution Approach 1:
The wedge element utilizes a curved or angled surface geometry to convert the linear pull force from the pull tab into radial clamping force. The curved surface of the wedge provides mechanical advantage, amplifying the applied force to generate sufficient tensioning force for effective bracing while maintaining ease of operation through simple pull tab actuation.
Solution Approach 2:
The wedge mechanism provides a mechanical advantage that amplifies the applied force. When the pull tab is actuated, the wedge geometry converts this small input force into a large radial clamping force through mechanical leverage. This mechanical amplification ensures sufficient tensioning force for effective bracing while keeping the operation simple and easy to perform.
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 assembly of wind turbine towers by allowing for easier and more cost-effective fastening of prestressing strands, reducing the complexity and expense associated with traditional methods.
Implementation Method 1
A spring can be provided in the sleeve, which suppresses the wedges when screwing tight. This can prevent accidental loosening of the wedges.
Implementation Method 2
The fastening unit is fastened by placing a multi-part wedge unit at a free end of the tendons
Data Source
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AI summary
This problem is solved by a method for erecting a wind turbine tower (200) having a plurality of tower segments (210) which are tensioned by means of tensioning members (400). A plurality of tensioning members (400) is provided and a fastening unit (500) is fastened on an end of the tensioning members (400). The fastening unit (500) is fastened by positioning a multi-part wedge unit (510) on a free end of the tensioning members (400), which consist of a plurality of tensioning strands (401). A sleeve (520) is placed over the wedge unit (510) and a pulling tab (530) is fastened on or to the sleeve (520). The pulling tab (530) has an opening (531). A cable (620) is fastened on or in the hole (531) of the pulling tab (530). The cable (620) with the fastening unit (500) and thus the tensioning members (400) is pulled upwards. The fastening unit (500) is fastened to a tower segment (210) to be fastened. The sleeve (520) is removed before the tensioning member (400) is tensioned.