Jd. Booker, ACOUSTIC-EMISSION RELATED TO INSTANTANEOUS STRAIN IN TASMANIAN EUCALYPT TIMBER DURING SEASONING, Wood Science and Technology, 28(4), 1994, pp. 249-259
Acoustic Emission (AE) was measured in 30 mm-thick backsawn and quarte
rsawn Tasmanian Oak (Eucalyptus regnans F. muell) boards drying at tem
peratures in the vicinity of 20-degrees-C. By varying the diffusion co
efficient used in a non-linear drying simulation program, calculated h
alf-thickness moisture profiles were matched to measured profiles in a
sample board. Once the measured and calculated drying behaviour was s
atisfactorily matched, the AE measured in an endmatched board closely
followed the surface instantaneous strain calculated with the program.
The AE activity increased once the surface instantaneous strain attai
ned the proportional limit. The AE is not simply related to drying tem
perature or humidity but rather to a complex interaction between the t
wo parameters.