Mechanical behavior of walnut ( Juglans regia L .) and cherry ( Prunus avium L .) wood in tension and compression in all anatomical directions. Revisiting the tensile / compressive stiffness ratios of wood.

The mechanical properties of walnut (Juglans
regia L.) and cherry (Prunus avium L.) woods, as frequent
raw materials in cultural heritage objects, have been investigated
as a function of the anatomical directions and the
moisture content (MC). The strength data are decreasing
with increasing MC, whereas the tensile strength in the longitudinal
direction is higher by factors of 1.5–2 compared
to the compression strength. Moreover, the inequality of
tensile and compressive stiffness is discussed, which is a
matter of debate since a long time. This so-called bimodular
behavior is difficult to describe in a generalized mode
due to the high data variability if tension and compression
properties are analyzed on different samples. If tensile and
compressive stiffness tests are performed on the same samples
of walnut and cherry wood, the ratio between these
properties is significantly higher than 1.
Keywords: cherry wood (Prunus avium L.), stiffness ratios,
strength ratios, tension and compression strengths,
walnut wood (Juglans regia L.)