Determination of elastic constants for scots pine wood using ultrasound

Öz

Elastic constants of Scots pine (Pinus sylvestris L.) wood grown in Turkey were investigated using non-destructive ultrasound tests. Elastic modulus in longitudinal and perpendicular directions (EL, ER, ET), shear modulus in principal planes (GLR, GLT, GRT) and Poisson ratios (ʋLR, ʋRL ʋLT, ʋLT, ʋRT, ʋTR) were calculated using cubic samples (20 mm) which were conditioned at 65 % relative humidity and 21 °C. Longitudinal and transverse ultrasonic sound velocities in fiber (L), radial (R) and tangential (T) directions were measured using 2.25 MHz and 1 MHz sensors, respectively. Transverse sound wave velocities at an angle of 45° to the L, R and T directions were also measured with a 1 MHz sensor in order to calculate the Poisson ratios. The predicted elastic modulus based on ultrasound in L, R, T directions were 10600, 1300 and 470 N/mm2, respectively. The predicted shear modulus based on ultrasound in LR, LT, RT planes were 1180, 1050 and 350 N/mm2, respectively. Poisson ratios varied between 0.04 to 0.95. Comparing the data available in the literature, elastic constants of scots pine determined using ultrasonic method were within the acceptable values.

Anahtar Kelimeler

• Elastic constants
• Prediction
• Scots pine
• Ultrasound

Sarıçam odununun elastik sabitlerinin ultrasonik yöntemle belirlenmesi

Öz

Türkiye'de yetişen sarıçamın (Pinus sylvestris L.) elastik sabitleri tahribatsız ultrasonik testler kullanılarak incelenmiştir. Boyuna ve liflere dik yönlerde elastikiyet modülleri (EL, ER, ET), ana düzlemlerde kesme modülleri (GLR, GLT, GRT) ve Poisson oranları (ʋLR, ʋRL ʋLT, ʋLT, ʋRT, ʋTR) % 65 bağıl nem ve 21 °C sıcaklıkta şartlandırılan 20 mm kenar ölçüsüne sahip kübik numuneler kullanılarak hesaplanmıştır. Lif (L), radyal (R) ve teğet (T) yönlerdeki boyuna ve enine ultrasonik ses hızları sırasıyla 2.25 MHz ve 1 MHz sensörler kullanılarak ölçülmüştür. Poisson oranlarını hesaplamak amacıyla L, R ve T yönlerine 45° açıyla enine ses dalgası hızları da 1 MHz sensörle ölçülmüştür. L, R, T yönlerinde ultrasona dayalı tahmin edilen elastik modül sırasıyla 10600, 1300 ve 470 N/mm2 bulunmuştur. LR, LT, RT düzlemlerinde ultrasona dayalı tahmin edilen kesme modülü sırasıyla 1180, 1050 ve 350 N/mm2 olarak hesaplanmıştır. Poisson oranları 0.04 ile 0.95 arasında değişmektedir. Literatürdeki veriler ile karşılaştırıldığında sarıçam odununun ultrasonik yöntemle belirlenen elastik sabitlerin kabul edilebilir değerler içerisinde olduğu görülmüştür.

Anahtar Kelimeler

• Elastik sabitler
• Tahmin
• Sarıçam
• Ultrasonik yöntem

Kaynakça

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