Inspection and Evaluation of Decay Damage in Japanese Cedar Trees Through Nondestructive Techniques    (View PDF)

Cheng-Jung Lin, Chia-Ju Lee, and Ming-Jer Tsai

Abstract: The purpose of this study was to investigate the standard values of living, undamaged Japanese cedar (Cryptomeria japonica) trees through different nondestructive techniques. This study also detects the stress wave velocity (V) and tomogram (VT), and resolves corresponding V maps of Japanese cedar trees with and without decay damage for tree risk assessment. A visual tree inspection form, with seven categories of tree damage, is proposed for tree hazard assessment. Different nondestructive evaluation parameters can serve as an index for diagnosing standard values (with or without decay). The VT and corresponding stress wave velocity maps of decay-damaged and damaged Japanese cedar trees can detect the general location and area of wood deterioration. The transversal acoustic velocity values increased with increasing diameter in undamaged trees, and the difference between the maximum and minimum V value of the trunks in undamaged trees fell within a range of constants. The proposed approach can be combined with other non-destructive techniques to better examine and confirm the situation of trees.

Keywords: Cryptomeria japonica; Japanese Cedar; Nantou; Nondestructive Technique; Stress Wave; Taiwan; Tomography; Tree Haz-ard Assessment; Visual Tree Inspection

https://doi.org/10.48044/jauf.2016.018