Strength properties

Strength properties

Date Published

27 August 2022

Document Type

Category

Author

TRADA
Summary

In general terms, steel and concrete are both homogenous, being uniform in structure, and isotropic, having the same strength properties in all directions. However, in order to understand how timber behaves as a structural material it is necessary to understand that it has different strength properties in the longitudinal and transverse directions, and that it is the arrangement of the cells in timber that determine its strength and behaviour under different loads. Understanding the structure of wood will explain, for example, why it is up to 40 times stiffer in the longitudinal direction than the transverse direction.

Key Information

Timber has different strength properties in the longitudinal and transverse directions, and it is the arrangement of the cells in timber that determine its strength and behaviour under different loads.

Many factors affect the strength properties of timber: for example material properties, and climatic and environmental growth conditions.

The Modulus of Elasticity (MOE) and the Modulus of Rupture (MOR) are the two most important factors in the way timber responds to stress in the application of a load.

Case studies

The new building is the headquarters of the Loch Lomond and Trossachs National Park Authority, which covers an area of over 700 square miles to the north and west of Balloch.

Walking into the new railway station at Abbey Wood, the immediate impression is of the elegant timber roof which arches over the interior, imparting a warm, natural quality to this large public space – more than 25 metres by 25 metres.