Problem 4.34

 

 

 

See example 4.3 instead of trying to find Ref. 4.26.

 

 

Shrinkage Value (assumption)

 

SV = 6/30 = 0.2% per 1% change in MC

 

 

Shrinkage

 

S = SV x d x Δ_MC = 0.002 x 13.25" x (19 - 10) = 0.2385"

depth after shrinkage = 13.25 - 0.2385 = 13.01"

 

 

Comparing to Chapter 7 of Wood Handbook

 

d₂ = d₁ (1 - (a - bM₂)/100) / (1 - (a - bM₁)/100) = 13.25" (1 - (6.031 - 0.215 x 10)/100) / (1 - (6.031 - 0.215 x 19)/100) = 13.02"

a and b depend upon species; values here are for non-redwood and non-cedar