%0 Journal Article
%T Non-Contact Velocity Measurement of  Japanese Cedar Columns Using  Air-Coupled Ultrasonics
%A Masumi Hasegawa
%A Misaki Mori
%A Junji Matsumura
%J World Journal of Engineering and Technology
%P 45-50
%@ 2331-4249
%D 2016
%I Scientific Research Publishing
%R 10.4236/wjet.2016.41005
%X The ultrasonic wave velocities of Japanese cedar columns were measured using a non-contact method. An air-coupled ultrasonic wave was propagated through the axial and lateral directions of wood. The velocities in the axial direction (V<sub>L</sub>) showed the minimum values around the pith. The averaged V<sub>L</sub> increased from 3600 m/s towards the outside of measurement area and attained the maximum values (=4010 m/s). The velocities in the lateral direction (V<sub>RT </sub>) showed no tendency among measurement points. The averaged V<sub>RT </sub> was 1450 m/s. The velocities obtained using the non-contact method showed a significant positive relationship with those obtained using the contact method. The averaged ratio of V<sub>L</sub> to V<sub>RT </sub> was measured to be approximately 2.2 to 2.8. These ratios were in agreement with those from a contact method. These findings suggest that it is possible to measure the velocity in Japanese cedar columns with the non-contact method by using air-coupled ultrasonics.
%K Air-Coupled Ultrasonics
%K Velocity
%K Non-Contact Method
%K Nodestructive Evaluation
%K Japanese Cedar
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=63364