strain measurement of wood

Project: Compression perpendicular to the grain in cross-laminated engineered wood-based products

The aim of this project was a better prediction and exploitation of the properties of wood in engineered wood-based products such as cross-laminated timber. A computational model was developed that can save time and efforts and also be used for product optimization.

This project was concluded in 2019.

About the project

Project manager
Thomas K Bader
Project members
Shaheda Tahmina Akter, Jan Oscarsson, Bertil Enquist
Participating organizations
Linnaeus University, Faculty of Engineering LTH
Financing organization
January 2017–December 2019
Building Technology (Department of Building Technology, Faculty of Technology)

More about the project

An important research question relates to the understanding of the relationship between the structure of wood and mechanical properties of wood products. The aim of this project is a better prediction and a better exploitation of material properties of wood in engineered wood-based products such as cross-laminated timber. A computer model, able to describe and predict the behaviour of CLT under compressive loading perpendicular to the grain, will be developed in this project. A computational model can save time and efforts required for experimental testing of wood products and can be applied for a product optimization.

A deterministic computational model

This project aims at the development of a deterministic computational model, able to describe causal relationships between the cylindrically orthotropic material behaviour of wood and the structural response of cross-laminated engineered wood-based products under compression perpendicular to the grain.

In this proposed project, we promote a combined experimental numerical approach in order to provide experimental evidence for model development, validation and calibration. Experimental investigations will be performed using advanced deformation measurement systems in order to visualize and quantify the effect of annual ring structures as well as load distribution effects. The effect of a globally superimposed shear load, in addition to compression perpendicular to the grain, on the local stress and strain field will be studied.

The development of the parametric computational model will allow studying the effect of the lay-up (i.e., number of laminations, lamination thickness, orientation, etc.), the effect of material characteristics (i.e., annual ring pattern, mechanical properties of the lamellas, etc.), as well as the effect of support and load configuration, on the global response of cross-laminated timber. Thus, the project is expected to enhance the understanding of structure-function relationships in CLT and thus, to strengthen the scientific knowledge for better exploitation of the inherent mechanical properties of wood in the design of sustainable timber structures.

The project is part of the research in the Wood Building Technology research group. It also includes a doctoral project, Connections and compression perpendicular to the grain in cross-laminated timber.

See also the press release for the project (9 December 2016).