Tension Element Detensioning with Active Force Control

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Solution Overview

Problem

Existing methods for relaxing tensioning elements in structures result in large overhangs and require significant space and materials, leading to uneconomical dimensions and high costs due to the need for caps and corrosion protection, with uncontrolled release movements posing additional challenges.

Innovation Solution

Employing an active power device, such as a hydraulic or pneumatic system, to control the release of tensioning elements by adjusting holding devices, allowing for a controlled and stepwise relaxation process using multiple holding devices to manage tension forces effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the projection of the tensioning element behind the anchorage arrangement is increased to ensure complete relaxation, then the tensioning element can be fully released, but the cap length and anchorage area increase significantly

Engineering Contradiction:
Improvecomplete relaxation of tensioning elementVSAvoidcap length
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

A tension-releasing device is introduced as an intermediary between the tensioning element and the anchorage arrangement. This device includes a holding device that engages with the tensioning element and a force device that applies controlled force to relax the tensioning element without requiring excessive projection length behind the anchorage.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the projection of the tensioning element is increased to allow complete relaxation, then the tensioning element can be fully released, but the anchorage area dimensions increase

Engineering Contradiction:
Improvecomplete relaxation of tensioning elementVSAvoidanchorage area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The tension-releasing device acts as a mediator that enables complete relaxation of the tensioning element while being positioned in the space between the two anchoring arrangements, thus avoiding the need for increased anchorage area dimensions.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If a passive damping device is used to control the release movement of the tensioning element, then some control is achieved, but truly controlled movement cannot be ensured

Engineering Contradiction:
Improvecontrol of release movementVSAvoidcontrolled movement of tensioning element
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The passive mechanical damping device is replaced with an active force device that can be controlled to apply specific forces to the tensioning element. This substitution enables truly controlled movement during relaxation, as the force device can actively regulate the release process rather than merely damping it passively.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The force device may utilize pneumatic or hydraulic systems to provide controlled force application to the tensioning element, enabling precise control of the release movement through fluid pressure regulation rather than passive mechanical damping.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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

Enables cost-effective and space-efficient relaxation of tensioning elements with controlled movements, reducing the need for extensive caps and corrosion protection, and minimizing installation space requirements.

Implementation Method 1

an active force device (148) which is supported on the base unit and is designed to exert a force on the tensioning element

Methodology Applied
Scientific EffectHydraulic force transmission: Hydraulic Press

Implementation Method 2

an active force device (148) which is supported on the base unit and is designed to exert a force on the tensioning element

Methodology Applied
Scientific EffectPneumatic force transmission: Gas Compressor

Data Source

PatentEP3358106B1Method and device for detensioning a tension element
Publication Date: 2025.09.03 DYWIDAG-SYSTEMS INTERNATIONAL GMBH
  • EP3358106B1 patent drawingFigure 1
  • EP3358106B1 patent drawingFigure 2
  • EP3358106B1 patent drawingFigure 3a

AI summary

The invention relates to a method for releasing a tensioning element (106) that is clamped between two sections of a structure (100). The method comprises the steps of: providing a release device (130) with at least one force device (148) that has a holding device (140) for establishing a holding engagement with the tensioning element (106); attaching the release device (130) to the structure (100) at a location between the two anchoring arrangements (102, 103); and bringing the holding device (140) of the at least one force device (148) into holding engagement with the tensioning element (106) to be released. According to the invention, the at least one force device (148) is an active force device.Furthermore, the method comprises the following steps: actuating the at least one force device (148) in order to take over the clamping force of the clamping element (106); releasing the anchoring engagement between the anchoring arrangement (102) and the clamping element (106); and actuating the at least one force device (148) in order to relax the clamping element (106).