Research into glued-in threaded rods in laminated wood
Project information
Location: Eindhoven (Eindhoven University of Technology)
Project type: Academic Research
Objective: Experimental, numerical, and analytical analysis of the pull-out strength of glued-in threaded rods in wood
Project description
Glued-in threaded rods constitute a high-quality joining technique within modern timber frame and laminated timber construction. They are primarily used for two critical structural purposes: transferring forces between structural elements and locally reinforcing wood in zones with high tensile stresses perpendicular to the grain to prevent splitting and cracking.
Despite their wide applicability, glued-in threaded rods are currently not included in Eurocode 5 (NEN-EN 1995), primarily due to the lack of a harmonised European product standard for structural wood adhesives. This research focused on resolving existing uncertainties regarding the failure behaviour and mechanical performance of this type of connection.
Research Methodology & Parameters
To obtain a comprehensive picture of the structural behavior, the pull-out strength of glued-in threaded rods in laminated timber was analyzed using a combination of physical laboratory tests (experimental), finite element modeling (numerical), and computational models (analytical).
Within the study, three specific influencing factors were investigated in depth:
Tolerances & Measurement Deviations: The effect of unintended misalignment and eccentric placement of the threaded rod in the bore hole on the final capacity.
Wood fiber direction: The influence of the angle between the force/axis threaded rod and the wood fiber (investigated at 0°, 45°, and 90°).
Combined load: The mechanical behavior under simultaneously occurring tensile and shear forces (combined stress state).
Elaborated parts
• Experimental test trials (scaled failure tests)
• Numerical FEM simulations of adhesive and stress distribution using ANSYS and Abaqus software
• Analytical verification and calculation model for Eurocode integration
Publications & Research Output
• E. Schijns – Glued-in threaded rods in laminated wood (TU/e Research Portal)