The Modulus of Elasticity of Hybrid Larch Predicted By Density, Rings Per Centimeter, and Age
Keywords:
Modulus of elasticity, wood density, age, rings per centimeter, larch, <i>Larix X eurolepis</i>Abstract
A total of 492 specimens from eighteen trees representing fast-growth larch were studied. The mean values of the modulus of elasticity (MOE), density, age, and rings per centimeter were determined for each. Mathematical models were developed to predict the MOE from the other parameters. Linear models are first presented showing the dependence of MOE on each of the three parameters, density, age, and rings per centimeter. A multivariate linear regression model is then developed for MOE as a function of all three parameters. The correlation coefficient of this model is 0.66, an improvement over each of the models for which each parameter is taken individually. A prediction of MOE by visual means alone, i.e., using only age and rings per centimeter in a linear model, is also presented. The correlation coefficient of this model is 0.58, which is superior to any of the parameters taken individually. In order to develop a model useful for extrapolation beyond the range of test data, a nonlinear model is presented. The parameters of this nonlinear model can easily be interpreted in terms of (1) the maximum attainable stiffness, (2) the ring age for maximum MOE growth rate vs. age, and (3) the shape parameter of the model. We found that the nonlinear model matched the data well and incorporated the realistic conditions of zero MOE at zero ring age and a limit on the maximum attainable MOE.References
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