Strain and cracks investigations on tropical green wood slices under natural drying: experimental and numerical approaches

This work presents the experimental study of natural drying and cracking of green wood slices of two tropical species. The tests were carried out on slices of Aucoumea klaineana P. and Pterocarpus soyauxii at uncontrolled temperature and relative humidity. To follow the strains, specifical targets were drawn on the slice in the radial and circular directions. The slice was placed in front of a camera to record the mass loss on a control specimen and to follow the displacement of the targets on a regular basis until the end of the tests. As results, the evolutions of radial and tangential displacements were calculated in a cylindrical coordinate and the fiber saturation point was deduced accordingly. In addition, the initiation and the crack propagation were followed in a green wood slice subjected to natural drying. At the end, finite element model was developed, and the obtained results were compared to experimental data. The results help to better understand and anticipate the behavior of green wood slices during desiccation. In addition, the potential areas of appearance and propagation of cracks were identified to reduce and prevent defects resulting from the primary processing of wood.