Nondestructive Evaluation of 2 by 10 Southern Pine Lumber

Efficient use of the available wood resources is necessary to sustainably meet the long-term demand for wood products. This paper presents research about the potential of using transverse and longitudinal vibration techniques to evaluate the bending modulus of elasticity MOE (Eb) and tensile properties (Et and UTS) of 2 by 10 No. 2 grade southern pine (Pinus spp.) lumber. A total of 285 lumber pieces were first nondestructively tested using longitudinal vibration (Director HM 200), transverse vibration (Metriguard E-computer), and proof-loading bending tests (Universal Instron Machine). Each specimen was then destructively tested in tension parallel to the grain to determine tension modulus of elasticity (Et) and ultimate tensile stress (UTS). Correlations between growth characteristics, physical, and mechanical properties were analyzed. Excellent correlative relationships between longitudinal and transverse dMOE with the elastic properties Eb, and Et were found. A strong correlation was also found between the elastic properties Eb and Et. The prediction of Eb was improved after adding density to the model. The estimation of UTS was also improved with the addition of density and a secondary nondestructive measurement. Nondestructive techniques are recommended to assess the mechanical properties of southern pine 2 by 10 lumber.