| dc.description.abstract | Ultrasonic-based methods ofnon destructive testing applied to wood have been intensively developed during the last decade. There are two parameters used to evaluate of wood based on ultrasonic method. ultrasonic velocity and atenuation. The main objective ofthis research was to analyze ultrasonic velocity characteristics ofwood beam. Three wood species were used in this research representing high, medium, and low density. The beam specimen of (8 x 12 x 200) cm from tectono (Tectono grandis), manU wood (Maesopsis eminii), and sengon (Paraserianthesfalcataria) were prepared in air dried condition. The ultrasonic wave propagation was measured by SylvatestDuo@. The dynamic st!lfness (MOEd) was gained based on Christoffel equation formulating correlation between the ultrasonic velocities and density. The results showed thaJ ultrasonic velocity propagation decreased by increasing wood density between species. On the other hand. in same species higher wood density caused increase in ultrasonic velocity propagaJiOll Statistical analysis showed thaJ no significant irifluence qf vertical position ofbeam in tree (bo/lom, middle. and top) on Vus and MOEd However, there was significant effict from measurement direction ofwave propagation (longitudinal. radial, andtangen/taO. Length dimensions were influenced by ultrasonic velocity values in which thase mlues decreased by increasing length dimensiOll | id |
