A fracture mechanics approach to the tensile strength perpendicular to grain of dimension lumber

Summary Six hundred short sections taken from 23 flatsawn 2x12-inch planks of construction grade Doughas-fir were tested in tension perpendicular to grain. Most of the specimens contained defects in the form of checks, knots, resin streaks, pitch pockets, and pith. Checks were found to be the major strength-reducing defect. The effect of checks could be analyzed effectively by using the concepts of fracture mechanics.