Effect of Incising on Bending Properties of Redwood Dimension Lumber.

摘要

Three incising patterns were evaluated for their effects on the important bending properties of dimension-size redwood lumber. Two of the patterns were open, not widely spaced, incisings; a third was a closely spaced diagonal pattern. Test material was above the fiber saturation point and included a range in specific gravity representative of redwood. Incising effects on bending properties of redwood varied with pattern and depth of incisions. Values for energy absorbed were reduced most; for modulus of elasticity, least; and for modulus of rupture, to an intermediate degree. Two open patterns of incising, on the average, reduced modulus of rupture about 10% and modulus of elasticity about 5%. A closely spaced diagonal pattern of incising caused about twice as much loss in strength.