USE OF LONGITUDINAL VIBRATION AND VISUAL CHARACTERISTICS TO PREDICT MECHANICAL PROPERTIES OF NO. 2 SOUTHERN PINE 2 x 8 AND 2 x 10 LUMBER

摘要

The objective of this study was to evaluate the accuracy of single MOE and MORand combined mechanical properties with visual characteristics to improve the prediction of 2 x 8 and 2 x 10 No. 2 southern pine lumber. This study evaluated the following variables: nondestructive tests, knots (knot diameter ratio [KDR] and knot area ratio), density, and mechanical properties (stiffness [MOE] and strength [MOR]). A total of 486 pieces were used, and linear regression models were constructed using stepwise selects to determine the best variables to estimate the MOE andMOR of southern pine lumber. The best single predictor for MOE and MOR was dynamic MOE (dMOE) followed by density. Among the two knot measurement methods used, the KDR best predicted stiffness and strength. For predicting the MOE, the variables dMOE and density were the best combination for 2 x 8 samples, and the combination for 2 x 10 samples was dMOE, density, and KDR. The results showed that the addition of knot measurements to the models is able to improve the prediction of mechanical properties.