Problem 4.17

See Problem 4.16 for reference design values.

 

 

NDS Appendix N tables N1 and N2

 

Property		Conversion Factor KF	Resistance Factor Φ
bending stress	Fb	2.16/Φb	Φb = 0.85
tension stress parallel to grain	Ft	2.16/Φt	Φt = 0.80
shear stress parallel to grain	Fv	2.16/Φv	Φv = 0.75
compression stress perpendicular to grain	Fc⊥	1.875/Φc	Φc = 0.90
compression stress parallel to grain	Fc	2.16/Φc
modulus of elasticity for stability calculations	Emin	1.5/Φs	Φs = 0.85

 

 

Nominal Design Values (psi) for No. 1 DF-L

 

Property		Dimension Lumber	Timbers
			Beams & Stringers	Posts & Timbers
bending stress	Fbn	1,000 x 2.16 / 0.85 = 2541	3,431	3,049
tension stress parallel to grain	Ftn	675 x 2.16 / 0.80 = 1823	1,823	2,228
shear stress parallel to grain	Fvn	180 x 2.16 / 0.75 = 518	490	490
compression stress perpendicular to grain	Fc⊥n	625 x 1.875 / 0.90 = 1302	1,302	1,302
compression stress parallel to grain	Fcn	1,500 x 2.16 / 0.90 = 3600	2,220	2,400
modulus of elasticity	E	1,700,000	1,600,000	1,600,000
modulus of elasticity for stability calculations	Emin-n	620,000 x 1.5 / 0.85 = 1,094,000	1,024,000	1,024,000