Detection of heart rot voids in trees using stress wave analysis

The ability to detect the presence of heart rot in living trees offers a significant improvement in the ability to manage a stand of timber. The Objective of the research was to determine if heart rot voids in log sections could be detected using stress wave analysis techniques. Six aspen log sections, representing the species and size of trees of most concern to the Alberta Department of Forestry, were investigated which contained various degrees of degradation. Nondestructive parameters were Obtained from the frequency spectra of induced stress waves and subsequently correlated to the degree of degradation in each log section. The stress wave analysis FIDE technique was able to identify not only the presence of heart rot voids, but also the extent of the void within the log section, with a correlation coefficient of 0.98. Thus, the research verified the feasibility of using the stress wave analysis NDE technique for detecting heart rot in log sections. The availability of such a technique would enable the monitoring of the progress of decay within a stand. Decisions can then be made as to the optimal time in which to harvest the stand to maximize the commercial yield