Deformation analysis of curved laminated structural wood elements

The deformations emerging in the laminated wood elements having straight and curved forms display differences when any loading is applied. The objective of this study is to determine the effect of the type of wood and time on the deformations in a curved structural element manufactured with the lamination method in case of loading or unloading. In the determination of the amounts of deformation, the leg of the sitting element in the form of a curve, which is used frequently in practice, was taken as the model. 60 specimens were prepared with 7-layer and in a curved form from the face, back and central layers of Eastern beech (Fagus orientalis Lipsky), sessile oak (Quercus petrea (Mattuschka) Lieb.) and chestnut (Castanea sativa Mill.), and for the other layers from black poplar (Populus nigra L.). The 60-min deformation test was applied to the specimens in accordance with TS 9215 (ISO 7173). The deformations emerging at the 3rd and 60th minutes of the loading and unloading periods were determined and the values were subjected to statistical analysis. According to this analysis, the type of wood and time in the loading and unloading periods was not effective on the amount of deformation. A 11 mm elastic deformation and a 4 mm plastic deformation on the leg of the model sitting element was determined and there was no progressive deformation (fatigue) within the envisaged period of time.