Dowel Bearing Strength
Wood Members
direction of load to grain
- Fe// and Fe⊥
- Hankinson formula for other angles (textbook section 6.8, NDS appendix J)
Load
DirectionBearing
StrengthTest
NumberYield
Load (lb)Block
Width (in)Bearing
Strength (psi)// to
grain4,993 psi 1 5,665 1.500 5,036 2 6,049 1.530 5,271 3 5,799 1.521 5,083 4 5,075 1.530 4,423 5 5,900 1.527 5,152 ⊥ to
grain1,877 psi 1 2,520 1.500 2,240 2 2,821 1.543 2,438 3 1,422 1.480 1,281 4 1,645 1.490 1,472 5 2,308 1.573 1,956
Small-diameter fasteners (<1/4"-diameter) have same dowel bearing strength regardless of angle of load to grain.
drilling vs no-drilling
Steel Side Plates
NDS appendix I
hot-rolled plates (t ≥ 1/4 in.)
Fe = 2.4Fu / 1.6 = 1.5Fu
cold-formed plates (t < 1/4 in.)
Fe = 2.2Fu / 1.6 = 1.375Fu
Glulams
Fe based on G of less-dense inner lams, unless fasteners are only in outer lams
Wood Structural Panels
species is usually unknown
NDS table 11.3.2B (from APA tests)
OSB, STRUCTURAL I plywood, Marine plywood
Fe = 4,650 psi
G = 0.5other grades of plywood
Fe = 3,350 psi
G = 0.42