Wechselwirkung zwischen der Anisotropie der Schwind- und?Quellma?e sowie Holzfeuchte-?nderungen in der Ebene von?gekr��mmtem Brettschichtholz

Findings on the differential shrinkage in the cross-section of solid timber as cylindrically orthotropic material are applied to the plane of curved softwood glulam. From an engineering point of view, the differential shrinkage in the plane of curved glulam is characterised by a ratio of longitudinal shrinkage to averaged shrinkage perpendicular to the grain of 1:24. For solid timber, the ratio tangential to radial is about 2:1. By means of modelling glulam as part of a circular ring it is shown that curvature variations are caused by both pronounced differential shrinkage in the plane of curved glulam and moisture content variations in the hygroscopic range of wood. This can result in constraining and internal stresses in structural systems.