Simulation of correlated modulus of elasticity and compressive strength of lumber with gain factor

This paper discusses a gain factor model for the simulation of correlated stationary material properties of lumber (modulus of elasticity and compressive strength) in standard normalized space. Coupled with trend and multivariate standard normal simulation models, the gain factor model has been used for simulation of nonstationary properties of lumber. The mathematical formulae of ensemble autocorrelation functions and power spectra have been obtained with test data based on nonlinear least square regression with constraints minimization. The method can estimate the spectrum of data profiles with few points which can be used to simulate the strength of lumber by the spectral representation method.