IMPACTS OF CLIMATIC CHANGES AND CREEP LOADINGS ON THE CRACKED DOUGLAS (PSEUDOTSUGA MENZIESII) TIMBER BEAM IN OUTDOOR CONDITIONS

摘要

The Douglas is one of the most used species in France, especially in the Auvergne-Rhone Alpes Regions. This species found in unprotected outdoor environment is a major resource for the wood industry. However, variations in moisture content (MC), relative humidity (HR) and temperature (T) coupled with creep, can weaken its mechanical resistance. The main objective of this work is to study the mechanical behaviour of cracked wood beams under climate changes (T, HR and MC), the long-term loadings and the defects of wood (cracks, knots, orientation of annual rings etc). In this study, the evolutions of the crack length and the crack opening are presented. The results show the influence of climatic changes on the sustainability of timber structures of Douglas beams.