ACOUSTIC-EMISSION CHARACTERISTICS IN WOOD CUTTING .1. EFFECTS OF THE GRAIN ANGLES ON THE AMPLITUDES OF ACOUSTIC EMISSIONS

To obtain basic information on the generating sources of acoustic emis sions (AE) in wood cutting, the effects of the slope angle of grain (p hi(1)) and the slope angle of grain on the cutting plane (phi(2)) on t he level and distribution of the amplitude of the AE generated in the cutting of spruce (Picea sp.) were investigated. For comparison, the l evel and distribution of amplitudes of AE generated in medium density fiberboard (MDF) cutting also were examined. The results are summarize d as follows: 1. Compared to cutting parallel to the grain, the AE lev el increased remarkably in the range of phi(1)=60-120 degrees and had a maximum at phi(1)=75 degrees. 2. With increasing phi(2), the AE leve l decreased slightly and reached a minimum at 45 degrees. It increased remarkably at a 0-90 cutting of phi(2)=90 degrees. 3. The form of the amplitude distribution showed a similar tendency. 4. The generating s ources of AE in wood cutting are discussed.