2D and 3D CT images

Project: CT scanning and the influence of knots in structural timber

The purpose of the project is to determine in detail, using computer tomography, the geometry of knots within timber, as well as to investigate density variations and fiber orientation in wood material close to knots. It also includes development of mathematical models that match the experimental results. In the long term, the project results should contribute to the determination of engineering properties such as stiffness and strength for wood, with higher accuracy than is possible today, also for application in everyday grading at sawmills.

Image: Results of a preliminary µCT investigation of a knot in a Norway spruce specimen, (a) a section through the knot (b) a 3D image of the knot and the late wood fraction of the connecting growth layers.

Project information

Project manager
Anders Olsson
Other project members
Thomas Bader, Linnaeus University; Thomas Seifert, Stellenbosch University
Participating organizations
Linnaeus University, Stellenbosch University
1 Jan 2018–31 Dec 2020
Building Technology (Department of Building Technology, Faculty of Technology)

More about the project

The purpose of the project is to contribute to the development of future methods for efficient grading of structural timber and engineered wood products. In order to achieve this, basic studies on the properties of the wood material close to knots are needed, since knots are critical to the properties of timber. Equipment to be used within the project is an X-ray computer tomography, a so-called CT scanner, similar to those used for medical purposes to provide three-dimensional images of human organs, tumors, etc.

In this project, the geometry of the knots inside the timber and the density variation and fiber orientation of the wood material in the vicinity of knots will be closely investigated. Transformation of the new knowledge from the CT scan into mathematical descriptions of density variations and fiber directions is included as well. Models, in turn, can be used to better determine the crucial mechanical properties, locally, for the wood material.

The project is part of the research in the Wood Building Technology research group.