Detection And Analysis Of Acoustic Emission Signals During Wood Slice Drying Process

Wood drying technology is a very important part during the wood processing. So, It is important to control the temperature, humidity, lumber moisture content during wood drying process to reduce energy consumption and improve efficiency.The main content of this paper is that: design a constant temperature humidity chamber and establish a set of acoustic emission signal detection analysis system based on LabVIEW. The system can realize the signal detection, storage, parameter extraction, spectrum analysis, and other functions. We used this system testing the acoustic emission signal produced by wood drying process. Through the collection, statistics and analysis of AE signals, we may find a control parameter to improve the quality of wood drying.The results of the study showed that, the drying AE signals of four types of branches slices had little difference. By statistical analyzing the parameters of50biopsy’s signals of four species, we found that in the same environment conditions, all the the statistical distribution of signal parameters had great similar characters. In the trials of analyzing the temperature influence of the drying acoustic emission signals, we found that there was only one type of AE signals under normal temperature drying condition, and during high temperature drying process, there was another type of signals in addition which was different from the typical signals produced during normal temperature. The above results showed that: the typical high frequency signals were produced by free water evaporation xylem, and the high amplitude, high-energy and long duration signals were due to the wood deformation process. Therefore, through the measurement and analysis of ultrasonic signals produced by wood drying process, we could provide a new thought to wood drying.