TANGENTIAL AND RADIAL DEFORMATION FIELD-MEASUREMENTS ON WOOD DURING DRYING

In a previous study, the deformation field measurement method on wood during drying was described. This paper discusses the deformation fiel d measurement results during drying to 8.2% moisture content on the ra dial and tangential surfaces. It also attempts to explain the observat ions by an approximate expression based on earlywood-latewood interact ion theory. The deformation on the radial surface varied between -0.7% and 7.5%. The actual measurements on the radial surfaces support prev ious work. Deformation measurements on the tangential surfaces were be tween -0.5% and 9.0%. Although the investigations were carried out on gross wood specimens, the results provide an insight into the extent t o which local density variation within the early- and latewood layers may influence the magnitude of surface deformation.