The Examination of the Principal Physical and Mechanical Properties of Acacia melanoxylon Plantation Wood

To better understand the physical and mechanical properties of Acacia melanoxylon plantation wood, the main physical and mechanical properties of seven-year-old Acacia melanoxylon plantation wood were measured, analyzed, and evaluated. The results indicated that the basic density of seven-year-old Acacia melanoxylon plantation wood was 0.458 g/cm³, and the oven-dry density was 0.471 g/cm³, the air-dry density was 0.502 g/cm³. The volumetric, tangential and radial air-dry shrinkage rates were 4.87%, 2.70% and 2.23% respectively, with the air-dry differential shrinkage of 1.21 and a volumetric shrinkage coefficient of 0.43. For the oven-dry shrinkage, the volumetric, tangential and rates radial were 9.29%, 4.97% and 4.52% respectively, with a differential shrinkage of 1.10 and a volumetric shrinkage coefficient of 0.43. In terms of mechanical properties, the bending strength, modulus of elasticity in bending, compressive strength parallel to the grain, and impact toughness were 87.0 MPa, 12130 MPa, 34.0 MPa, and 78.1 KJ/m² respectively. The hardness of the end grain, tangential surface, and radial surface were 4368 N, 3472 N, and 3627 N respectively. The comprehensive strength of the wood was 120.1 MPa, and the comprehensive quality coefficient was 2641.92 × 10⁵ Pa, belonging to high-grade material.