Holes in beams

The aim of the project is to optimize existing timber structures and the development of design tools/methods, processes for drilling holes in solid timber beams, thus increasing the competitiveness of timber construction.

The holes placed in the pure moment regions had lower stresses perpendicular to the fibers compared to the holes in the screw-dominant zones.

The external steel plates reduced the stresses at the periphery of the hole by minus 19 percent in beams with holes in pure moment and minus 30 percent in beams with holes in screw-dominant zones. Internal 45֯ inclined screws did not take tensile stresses perpendicular to fibers in pure moment loading.

In the screw area, they significantly reduced these stresses.

• 40 % when using 6.5 mm diameter and 220 mm screws
• 45% when increasing the diameter of the screws from 6.5 mm to 8.2 mm.

Field: Industrial wood construction
Budget: 215,000 SEK
March 2020 - January2022
Project leader: Sven Berg, Luleå University of Technology
Funding: This project is funded by TCN.