Nondestructive evaluation of the tensile properties of structural lumber from the spruce-pine-fir species grouping: relationship between grain angle and energy loss

Abstract

This study was undertaken to examine the relationship between lumber grain angle and the energy loss characteristics of structural lumber. A random sample of 100 spruce–pine–fir lumber specimens was obtained from a local lumber yard. Grain angle was measured at numerous locations for each specimen with equipment that uses a dielectric nondestructive testing technique. A commonly used free transverse vibration test, in which the specimens were simply supported in a flatwise bending mode, was used to determine the energy loss characteristics of the specimens. Increases in grain angle resulted in greater energy loss. A statisically significant positive correlative relationship was found between grain angle and energy loss. More importantly, based on results from this study, energy loss measurements may be useful for detecting lumber with low strength values.

Citation

As, Nusret; Senalik, C. Adam; Ross, Robert J.; Wang, Xiping. 2020. Nondestructive evaluation of the tensile properties of structural lumber from the spruce-pine-fir species grouping: relationship between grain angle and energy loss. Res. Note. FPL-RN-0382. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 14 p.