Time-domain acoustic emission (AE) parameters were monitored during the drying of 25- and 50-mm-thick California black oak ( Quercus kelloggii ). Consistent drying conditions (82 C dry bulb temperature/43 C wet bulb temperature) were used throughout the experiment, and an AET 5500 acoustic emission monitoring system was used to monitor AE activity. AE event rates for both thicknesses were similar, with approximately 90% of all activity occurring during the initial 15 to 20 hours of drying, when the average moisture content was still above 50% (oven-dry basis). Active propagation of surface checks was consistently associated with the occurrence of an increasing number of high amplitude events (i.e., those between 60 and 79 dB), although nonvisible micro-failures could have been associated with the large number of lower amplitude events. The high amplitude events typically comprised less than 1% of all events occurring during a given run. Surface-mounted transducers did not detect AE associated with the internal checking that occurred in all test samples.
[1]
J. Milburn.
Cavitation studies on whole Ricinus plants by acoustic detection
,
1973,
Planta.
[2]
M. Suzuki,et al.
Acoustic emission during lumber drying
,
1990
.
[3]
Jiro Umetsu,et al.
Feedback control for drying Zelkova serrata using in-process acoustic emission monitoring
,
1987
.
[4]
Masahiko Suzuki,et al.
Prediction of Lumber Checking during Drying by Means of Acoustic Emission Technique
,
1985
.
[5]
W. Simpson,et al.
Use of acoustic emissions to control drying rate of red oak
,
1985
.
[6]
M. Tyree,et al.
Cavitation Events in Thuja occidentalis L.? : Utrasonic Acoustic Emissions from the Sapwood Can Be Measured.
,
1983,
Plant physiology.
[7]
Y. Kagawa,et al.
Acoustic emission generation in the process of drying hardwoods
,
1983
.
[8]
W. Simpson,et al.
Use of acoustic emissions to identify high levels of stress during oak lumber drying.
,
1980
.