Fracture energy approach for the identification of changes in the wood caused by the drying processes

Specific fracture energy measurements were applied to identify changes caused by wood-drying processes of solid wood. Specimen design and geometry as well as parameters and specifications for a fracture energy test were determined experimentally. The specific test set-up was applied on plantation teakwood sample sets of standard as well as alternating convection kiln dryings and one oven drying. The results show that alternating changes of the drying temperature along with the equilibrium moisture content (EMC) in a kiln schedule have a small but significant decreasing effect on the specific fracture energy in the radial/longitudinal as well as the tangential/longitudinal testing direction. Furthermore, oven drying at constant high drying temperature along with low EMC did not result in a significant change of specific fracture energy compared with standard drying, but caused greater scattering values in both transverse crack propagation systems.