Dowel Bearing Strength

 

Wood Members

direction of load to grain

• F_e// and F_e⊥
• Hankinson formula for other angles  (textbook section 6.8, NDS appendix J)

 

 

 

Load Direction	Bearing Strength	Test Number	Yield Load (lb)	Block Width (in)	Bearing Strength (psi)
// to grain	4,993 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 grain	1,877 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.)

F_e = 2.4F_u / 1.6 = 1.5F_u

 cold-formed plates  (t < 1/4 in.)

F_e = 2.2F_u / 1.6 = 1.375F_u

 

 

Glulams

F_e 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

F_e = 4,650 psi
G = 0.5

other grades of plywood

F_e = 3,350 psi
G = 0.42