Acoustic Emission and Acousto-Ultrasonic Techniques for Wood and Wood-Based Composites-A Review

摘要

This review focuses on the feasibility of acoustic emission (AE) and acoustic-ultrasonic (AU) techniques for monitoring defects in wood, particularly during drying. The advantaged and disadvantages of AE and AU techniques are described. Particular emphasis is placed on the propagation and attenuation of ultrasonic waves in wood and the associated measurement problems. The review is divided into two sections, acoustic emission techniques and acousto-ultrasonic techniques. It includes historical background on the techniques as well as applications for wood and wood products. Because much research on nondestructive tests for wood has been published only in Japanese, considerable attention is given to those publications.