INFLUENCE OF TIMBER HUMIDITY IN THE VELOCITY OF PROPAGATION OF ULTRASOUND

摘要

The presence of humidity in materials is known that it interferes in the propagation of ultrasonic waves. However, we know little about the influence of timber moisture in ultrasound. The present work will study this effect, with the use of Swiss equipment, known commercially as Sylvatest~(~R). In order to do this, 30 timber specimens were made from Eucalyptus grandis, used as structural material in Brazil mainly in glued laminated beams. Afterwards, other species will be studied. The velocity of ultrasound was analyzed in timber longitudinal, radial and tangential directions, for moistures varying from 15% to 60%. The results will be of great importance for later use of ultrasound in obtaining timber properties in the laboratory, as well as the quality control of timber in natural conditions.