Quality Assessment of Artocarpus heterophyllus Log Using Nondestructive Evaluation Techniques

Trees are vital resources to human ecology. Many trees, wooden logs and timbers lose their quality when they degrade due to fungal decay and insect attacks. In this work, stress wave method and radiography technique are the Nondestructive Evaluation (NDE) tools employed to check the presence of the defects in an Artocarpus heterophyllus wooden log. The influence of these defects, especially, the fungal decay on wood quality is studied by introducing an artificial defect and the resulting properties obtained are evaluated using stochastic approaches. A theoretical model for the distribution of the wood properties is proposed using Radon transform and the results are compared with the path analysis of the stress wave velocities in random cross-sections of the wood. Additionally, the variability of the properties for different grain angles is calculated using Hankinson equation. Further, the results are analyzed statistically using Weibull distribution and effect size to inspect the quality and invasiveness of the defects, respectively. Results show that a reasonable prediction of the properties can be made from the analytical formulation and the Weibull modulus can be used to quantify the wood quality. Finally, the values of Weibull modulus and effect size are compared and validated for the two NDE techniques.