Effect of density and propagation length on ultrasonic longitudinal wave velocity in some important wood species grown in Turkey

Abstract

In solids, density is an important factor that determines lots of properties such as mechanic behavior. Mechanic properties of materials can be determined by static and dynamic tests. Ultrasonic measurements are one of the non-destructive test methods and are being applied to lots of field for determination of wide range of properties. When literature in wood science reviewed, it’s seen that researches did not make a consensus on the effect of density on ultrasonic wave velocity. Also, propagation length is another issue that has close relations with ultrasonic waves. From this point of view, effects of density and propagation length on ultrasonic longitudinal wave in Oriental beech, Scots pine, Black pine and Turkish red pine woods were investigated in this study. 20x20 cross-cut and 20, 30 and 40mm L direction samples were used to perform measurements. All samples acclimatized at 20±1 °C temperature and 65% relative humidity. Then, ultrasonic measurements performed using OLYMPUS EPOCH 650 flaw detector and 2.25MHz contact type transducers. According to the results, MC of the samples were calculated around 12% and up to 25.49% increase in velocity observed when sample length increased from 20mm to 40mm. Coefficients of determination between density and velocity were ranged from 0.78 to 0.94. Therefore, it’s concluded that both propagation length and density have positive effect on ultrasonic wave velocity in these woods.

Keywords

• ultrasonik
• doğu kayını
• sarıçam
• karaçam
• kızılçam
• yoğunluk
• yayılım uzunluğu
• ultrasonic
• oriental beech
• scots pine
• black pine
• turkish red pine
• density
• propagation length