Modulus of Elasticity and Bending Strength of Squared Timber with Wane of Spruce and Larch

Abstract

Historical wooden structures are made of round timber or frequently of squared timber with wane, in southern European countries also known as Uso Fiume and Uso Trieste. Knowledge of the mechanical properties of these load-bearing structures is very important in their assessment and maintenance. In two research projects undertaken in cooperation with IVALSA/CNR, TIS Techno Innovation South Tyrol, Microtec and Lignaconsult, more than 750 spruce and larch beams were subjected to bending fracture tests to determine their mechanical properties. Using existing datasets, a method was developed to determine the modulus of elasticity of an irregular cross section which varies along the length of the beam. If the effective cross-section geometry of a wooden structure made from squared timber with wane is known, the elasticity behaviour and the load-bearing capacity can be defined using the calculated mechanical properties.