esmail rastbod

The walnut tree is one of the most important species in Europe, Asia and Iran, which is used in various industries such as furniture, veneer, and construction due to its high resistance and beauty. In this research, walnut trees from two different geographic locations, one from the forests in the north of Iran (Noor) and the other in the west of Iran (Shahrkord), were selected. We studied physical properties including dry density, basic density, shrinkage, and mechanical properties including bending strength, modulus of elasticity, compression parallel to the grain, shear, tensile parallel and perpendicular to the grain, tangential and radial screw withdrawal strength and toughness. In this research, standards 3129 and ASTM D143-14 were used to perform physical and mechanical tests, respectively. The moisture content of all samples during mechanical tests was 12%. The average dry density of Noor and Shahrekord walnuts was 0.61 and 0.57 (g/cm3) respectively. The results of variance analysis showed that the characteristics and physical resistances of these two species were not significantly different except for dry density, radial, tangential and volumetric shrinkages. However, due to the higher density of Noor species, it showed higher mechanical resistance compared to the Shahrekord species.