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EP-4741568-A1 - SYNTHETIC FIBER BASED TENDONS

EP4741568A1EP 4741568 A1EP4741568 A1EP 4741568A1EP-4741568-A1

Abstract

A tendon (10, 20, 30) for technical constructions, especially for use as tension leg and/or for stabilizing a structure of a wind turbine, comprises: a) A load-bearing core (11, 21, 31) comprising or consisting of a plurality of individual synthetic fiber-based strength members (11a, 21a, 31a); b) An enveloping layer (12, 22, 32) of synthetic material surrounding the load-bearing core (11, 21, 31).

Inventors

  • HUANG, Pierre

Assignees

  • Aritec Holding AG

Dates

Publication Date
20260513
Application Date
20241107

Claims (16)

  1. A tendon (10, 20, 30) for technical constructions, especially for use as tension leg and/or for stabilizing a structure of a wind turbine, the tendon comprising: a) A load-bearing core (11, 21, 31) comprising or consisting of a plurality of individual synthetic fiber-based strength members (11a, 21a, 31a); b) An enveloping layer (12, 22, 32) of synthetic material surrounding the load-bearing core (11, 21, 31).
  2. The tendon according to claim 1, whereby the enveloping layer (12, 22, 32) of synthetic material surrounding the load-bearing core (11, 21, 31) is not materially bonded to the load-bearing core (11, 21, 31) and/or an outermost layer of the synthetic fiber-based strength members (11a, 21a, 31a) is not embedded in the enveloping layer (12, 22, 32).
  3. The tendon according to any of preceding claims, whereby the enveloping layer (12, 22, 32) comprises or consists of an extruded layer, especially a seamless extruded layer.
  4. The tendon according to any of preceding claims, whereby the enveloping layer (12, 22, 32) comprises or consists of a wrapping foil, whereby, in particular, the wrapping foil comprises a connecting seam (22.1), e.g. a welding seam, running along the longitudinal direction (L) of the tendon, in particular along the entire length of the tendon.
  5. The tendon according to any of preceding claims, whereby the synthetic material of the enveloping layer (12, 22, 32) is selected from thermoplastic polyurethane (TPU), thermoplastic elastomers (TPE, TPEE), and/or polyethylene (PE).
  6. The tendon according to any of preceding claims, whereby the individual synthetic fiber-based strength members (11a, 21a, 31a) comprise or consist of carbon fibers, aramid fibers, high-density polyethylene fibers, glass fibers, basalt fibers, polyester fibers, and/or LCP fibers.
  7. The tendon according to any of preceding claims, whereby the individual synthetic fiber-based strength members (11a, 21a, 31a) comprise or consist of synthetic fiber cords, synthetic fiber strands and/or synthetic fiber ropes.
  8. The tendon according to any of preceding claims, whereby the individual synthetic fiber-based strength members (11a, 21a, 31a) are aligned in parallel without being twisted.
  9. The tendon according to any of claims 1 - 7, whereby the individual synthetic fiber-based strength members (11 a, 21a, 31a) are twisted together.
  10. The tendon according to any of preceding claims, whereby the tendon does not comprise any metallic strength members and/or metallic reinforcement layers, and/or the tendon is free of metallic elements.
  11. The tendon according to any of preceding claims, whereby the individual synthetic fiber-based strength members (11a, 21a, 31a) are essentially identical with respect to their structure and/or with respect to a property selected from tensile strength, length and/or diameter.
  12. The tendon according to any of preceding claims, whereby a breaking force of the tendon is at least 500 kN, in particular at least 5000 kN, for example at least 10000 kN or at least 30000 kN and/or a diameter of the tendon is in the range of 50 - 450 mm, in particular 50 - 350 mm or 350-450 mm.
  13. A wind turbine (200), especially a multi-rotor wind turbine, comprising a tendon (10, 20, 30) according to any of claims 1 - 12, whereby, preferably, the tendon is arranged as a structural component, especially as a tension member, for stabilizing a structure of the wind turbine, in particular for stabilizing a support and/or a beam that carries a main rotor; and/or the tendon is arranged in a multi-rotor wind turbine to interconnect two support elements (202a, 202b), e.g. beams, carrying the main rotors of two individual wind turbines (201a, 201b).
  14. A tension-leg platform (101), especially comprising an installation for the offshore production of oil, gas and/or renewable energy (102), whereby the tension-leg platform (101) is connected with seabed anchors (103) via one or more tendons (10, 20, 30) according to any of claims 1-12.
  15. Method for producing a tendon (10, 20, 30) according to any of claim 1 - 12 comprising the steps of: a) providing or producing a load-bearing core (11, 21, 31) comprising or consisting of a plurality of individual synthetic fiber-based strength members (11a, 21a, 31a); b) surrounding the load-bearing core (11, 21, 31) with an enveloping layer (12, 22, 32) of synthetic material.
  16. Use of a tendon (10, 20, 30) according to any of claims 1 - 12 as a tension leg and/or for stabilizing a structure of a wind turbine, especially a multi-rotor wind turbine.

Description

Technical field The invention relates to a tendon for technical constructions, especially for use as tension leg and/or for stabilizing a structure of a wind turbine as well as a method for producing such tendons. Further aspects of the invention are related to the use of specific tendons for as a tension leg and/or for stabilizing a structure of a wind turbine, especially a multi-rotor wind turbine, and to a wind turbine or a tension leg platform comprising a specific tendon. Background art In engineering and construction, a "tendon" usually refers to a high-strength cable or bar that provides tension in a structure and/or transmits tensile forces. Tendons are essential in modern engineering, enabling the construction of lighter and more efficient structures. For example, in post-tensioned concrete construction, tendons are placed within ducts in concrete elements. Once the concrete has cured, the tendons are tensioned and anchored, allowing the concrete to bear higher loads and resist cracking. Also, tendons are used in the construction of bridges and high-rise buildings to enhance structural integrity and load distribution. They help manage forces in the structure, improving its stability and durability. In tension-based constructions, tendons play a critical role in maintaining shape and stability by holding various components under tension. A special type of tendons are so called tension legs. A tension leg is a type of cable used primarily in offshore installations, particularly in tension leg platforms (TLPs) for oil or gas exploration, or in renewable energy production, e.g. in wind energy production. These platforms are anchored to the seabed using vertical tension legs, which provide stability and allow the platform to float above the water. In particular, tendons play a crucial role in stabilizing the structure and optimizing performance of multi-rotor wind turbines, especially on offshore platforms. These systems represent an innovative approach to harnessing wind energy in offshore regions featuring multiple smaller rotor turbines mounted on a single floating platform. In this regard, on the one hand, tendons are required as tension legs to anchor the floating platform to the seabed, providing stability against wind forces and wave action. This prevents excessive movement and ensures the turbines maintain optimal alignment with the wind. On the other hand, in multi-rotor systems, tendons help to distribute the loads from the individual turbines evenly across the platform. This reduces stress on specific areas, enhancing the overall structural integrity. Tendons are typically made from high-strength steel, designed to withstand significant tensile forces. The required tension or tensile force of tendons used as tension legs usually is at least 300 tons. Tendons used for multi-rotor wind turbines may a tension or tensile force up to 800 tons or even up to 3'000 tons. However, the large diameters required for producing such kind of tendons and the heavy weight of steel significantly limits the application of tendons in heavy-duty applications. Thus, there is still a need to develop improved solutions that do not have the disadvantages mentioned above or have them to a lesser extent. Summary of the invention It is the object of the invention to provide improved tendons. Especially, the tendons should be as light as possible and at the same time have the highest possible tensile strength. In particular, the tendons should be suitable for use as tension legs for offshore installations and/or for stabilizing the structure and/or optimizing performance of wind turbines, in particular multi-rotor wind turbines, especially on offshore platforms. The solution of the invention is specified by the features of claim 1. Accordingly, the core of the invention relates a tendon for technical constructions, especially for use as tension leg and/or for stabilizing a structure of a wind turbine, in particular a multi-rotor wind turbine, the tendon comprising: a) A load-bearing core comprising or consisting of a plurality of individual synthetic fiber-based strength members;b) An enveloping layer of synthetic material surrounding the load-bearing core. The tendon according to the invention turned out to be highly beneficial. When compared with steel-wire based tendons, the weight of the tendons can be reduced significantly thanks to the synthetic fiber-based strength members and the enveloping layer of synthetic material while the breaking force can be kept at a high level. Furthermore, tendons according to the invention can be produced with rather small diameters while still having a high breaking force. Thereby, the enveloping layer of synthetic material allows for protecting the load-bearing core and to adapt it to specific requirements by selecting an appropriate material, thickness, surface structure and the like. Likewise, the load-bearing core can be adapted to different requirements, e.g. by providing cores