Stochastic Model for Modulus of Elasticity of Lumber

A model was developed for generating the lengthwise variability in modulus of elasticity (MOE) of lumber. A limited grade selection of southern pine visual and machine stress-rated (MSR) grades formed the basic data base, A second-order Markov model was used to generate serially correlated MOE's along 30-inch segments for a piece of lumber. Modulus of elasticity indexes were obtained by dividing each correlated MOE by the average MOE of the piece of lumber. The MOE of each segment was obtained by multiplying the MOE indexes by a single random observation from a distribution of MOE. The distribution characteristics of the generated MOE values are preserved, and the first- and second-order lengthwise serial correlations are preserved