Behavior of Acoustic Emission Generation during Tensile Test Perpendicular to the Plane of Particleboard Particularly, Effect of Internal Structure Factor of Board

摘要

This investigation was concerned with the effect of internal structure factor of particleboard on the characteristics of acoustic emission (AE) during internal bond testing. The tensile tests perpendicular to the plane of hoard were conducted with the aid of AE monitoring system for handmade particleboards having various internal structure factors, such as particle size, board density, board thickness and resin content. Especially, the effects of particle size on the internal bond strength and AE generation behavior were studied.The tensile strength (IB) of particleboard was affected by particle size, board density, board thickness, resin content and schedule of hot-pressing. Generally, the higher the value of IB was, the more the cumulative AE event counts (T_(AE)) were monitored therefore, it was considered that IB was closely related to T_(AE). The ratio (R_a) of the stress level at the initiation of AE generation (#sigma#_G) to that at failure (IB) was negatively correlative to either of IB or T_(AE).Furthermore, from the results of AE measurement with several threshold levels, it was confirmed that the particleboard made of larger particles generated higher amplitude and more AEs than that made of smaller particles. And it was also confirmed that #sigma#_G was higher in the board made of smaller particles, because of reduction of amplitude of AE to be detected with AE sensor.