The Study On Acoustic Emission Characteristics In Wood Transitional Cutting

Acoustic emission(AE) technology ,as a completely new nondestructive detection method ,has been used in many fileds in some developed countries. They have progressed some researches in AE and used it in wood industry.As far as domestic wood processing filed , AE technology has been gradually used in nondestructive testing and monitoring drying process of wood and wood product ;but it hasn't been used in wood cutting so far .The paper focuses on discussing AE characteristics in wood transitional cutting and influences of wood annual ring on AE .The main work included in the thesis is shown as follows:1. Based on the fact that the wood cutting knife and workpieces keep moving in wood cutting experiment ,we explore the appropriate position placing the AE sensor on .After collecting the AE signal ,we need to extract the useful part from the original signal . Then we tried to find out the useful method to remove noise signal and at last we carried out it by making uses of Matlab wavelet toolbox .2. we analyse the possible AE sources in wood cutting . By studying the AE signal in a cutting period ,we got the conclusion that the cutting depth has a obvious influence on AE. The larger the cutting depth is , the stronger the AE is ; on the contrary ,the smaller the cutting depth is , the weaker the AE is .3. In longitudinal-end transitional cutting , we study AE characteristic by waveform analysis method and parameter analysis method . we contrast root mean square value (RMS) and ringing counts ,then analyse the possible AE sources in longitudinal-end transitional cutting,and build the relation between ringing counts and surface roughness .4. In longitudinal -transverse transitional cutting ,we contrast root mean square value (RMS) and ringing counts , then analyse the possible AE sources in longitudinal -transverse transitional cutting , at last build the relation between surface roughness and ringing counts.5. We study the influences of the wood annual ring on AE and built the relation between surface roughness and ringing counts similarly.