The Analysis Effect of Selected Factors on the Shear Strength of Woodbark at Different Wood Species

The bark as a product of the dividing of wood and cork cambium consists of a set of protective layers of cells, which protect the living tissue (cambium) from the external environment and separate the bark from the wood. The structure of bark as a component of a living tree is completely different from wood. This article describes the testing of the adhesion of wood/bark in the longitudinal and tangential anatomical direction during the dormant and growing season on three choice wood species (oak, beech, and spruce). The results show a remarkable influence of the wood species and anatomical direction, as well as period of vegetation (dormant or growing season). All wood species had higher values of shear strength in the longitudinal direction compared to the tangential direction. The highest average values in the longitudinal direction were measured in the dormant period for sessile oak (0.49 MPa) and beech (0.48 MPa). The lowest value of shear strength in the longitudinal direction was measured for spruce (0.36 MPa). During the growing season, the highest average shear strength values were also measured in the longitudinal direction at beech (0.46 MPa) and oak (0.39 MPa). The lowest value of shear strength in the longitudinal direction was measured similarly for spruce (0.26 MPa)