Development of a Pretensioning Anchorage for Sand-Coated CFRP Tendons: Modeling and Validation

Area of Science:

• Materials Science
• Civil Engineering
• Structural Analysis

Background:

• Prestressing of precast elements often utilizes temporary anchors for carbon-fiber-reinforced polymer (CFRP) tendons.
• Understanding the mechanical behavior of these temporary anchorages is crucial for efficient manufacturing processes.

Purpose of the Study:

• To perform a finite element (FE) analysis of a temporary anchor system for sand-coated CFRP tendons.
• To validate the FE model through experimental measurements of strain distribution.
• To assess potential failure mechanisms within the anchorage system.

Main Methods:

• Finite element (FE) analysis of a conical metal barrel and polymer wedge anchor.
• Experimental characterization of the soft contact between polymer wedges and sand-coating.
• Fiber optical sensing for measuring strain distribution in the CFRP tendon.
• Implementation of a failure criterion according to Puck.

Main Results:

• The FE model accurately predicted the strain distribution in the CFRP tendon under load.
• Significant stress concentration was identified at the front of the anchorage.
• Good agreement was observed between FE model predictions and experimental results.
• A method for assessing fiber or interfiber failure was implemented.

Conclusions:

• The developed FE model is a reliable tool for analyzing the behavior of temporary CFRP tendon anchors.
• The study highlights critical stress concentrations that inform anchor design and performance.
• The implemented failure criterion allows for the prediction of potential material failure.