The Sling – Improved Anchorage for CFRP Tension Members

14015/TUB: The Sling – Improved Anchorage for CFRP Tension Members


Carbon fibers display a high tensile strength and a high stiffness while simultaneously having a low mass. Due to their high strength in fiber direction, carbon fiber reinforced plastics are especially suitable for bar-shaped tension members. A special challenge hereby is the anchoring of the carbon fibers that would be suitable for the material. Through the anchorage, the fibers at the anchoring point are often weakened or exposed to additional strain, so that a corresponding cross-section of the fibers experiences early failure prior to reaching its actual bearing capacity.

It was thus the objective of the present invention to provide an improved tension member made of carbon fiber-reinforced plastic (CFRP) by changing the manufacturing method and increasing the bearing capacity of the loop to up to 100%.

Technical Description

For this purpose, the invention discloses a multi-layer anchoring with at least one loop formed by double-sided carbon fibers. It serves to attach bendable CFRP tension members.

 To form the anchoring, the carbon fibers are alternately placed around the deflecting body and are embedded between the incoming fiber strands. In this way, the fibers overlap each other so that the total cross section at the level of the deflection is greater than that of the incoming fibers. The frictional connection of the fibers is achieved by the solidification of the plastic (for example by increasing the temperature, chemical reaction of the coating, injection of the plastic, application of lateral pressure) in the entire or only in some areas of the overlap.


Prototype of the sling (bearing load 200t)



Anwendungsmöglichkeiten / Possible applications:

As the sling is formed only locally at the end of the fibers it can be used in various applications with respectively different dimensions possible, like for example as an individually designed component, or as part of a support structure for building structures such as buildings, bridges, tunnels, sports facilities, towers, tents, or also for mobile machines such as cranes, ships, wind turbines.

Interested? Contact Us! Interested? Contact Us!
Show all techoffers Vorteile / Benefits:
  • Tension member can be formed in any desired length and bearing load
  • Failure of the element at the anchorage point with applied traction force can be avoided
  • Pultruded bar-shaped profiles with any desired cross-section can be used for forming the tension element
Entwicklungsstand / Development status:


Reifegrad / Maturity level:


Schlagworte / Tags:
anchoring, carbon fibers, deflecting body, loop, tensile strength, tension element
Schutzrechte / Property rights:

DE, EP, US - pending

Patentinhaber / Patent holder:

Technische Universität Berlin

Möglichkeiten der Zusammenarbeit / Possible cooperation:
  • R&D Cooperation
  • Patent Sale
  • Licensing

Ansprechpartnerin / Contact Person:
Ina Krüger

Tel.: 030 314-75916
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