Kavak odununun rutubete bağlı eğilme özellikleri

Öz

Rutubetin, Populus x canadensis M.'in fiziksel (yoğunluk) ve mekanik (Eğilme direnci-MOR, Elastikiyet modülü-MOE) özellikleri üzerindeki etkisi üç nokta eğme testi ve ultrasonik test yöntemi ile belirlenmiştir. Örnekler 20±1 °C'de ve %45, 65 ve 85 bağıl nemde şartlandırılmıştır. Hesaplanan ultrasonik boyuna dalga hızı (VLL) dinamik MOE'yi (4549 ila 4735 MPa) belirlemek için kullanılmış ve statik MOE (5461 ila 5910 MPa) ile karşılaştırılmıştır. Statik MOE değerleri dinamik değerlerden yaklaşık %15.3 ila %28.1 daha yüksektir. Rutubetten en çok etkilenen özellik olan MOR değerleri, rutubetteki artışla birlikte 70.1 MPa'dan 51.3 MPa'ya düşmüştür. Pearson korelasyon katsayıları 0.52 (MOR vs VLL) ile 0.94 MOEdyn vs VLL) arasında değişmektedir. R² değerleri 0.187 (%85 bağıl nemde VLL vs MOR) ile %0.94 (%65 bağıl nemde VLL vs Edyn) arasında değişmiştir.

Anahtar Kelimeler

• Populus x canadensis
• Eğilme direnci
• Elastikiyet modülü
• Ultrases

Moisture dependent bending properties of poplar

Öz

The influence of moisture on the physical (density) and mechanical (modulus of rupture-MOR, modulus of elasticity-MOE) properties of Populus x canadensis M. were figured out by three three-point bending tests and ultrasonic testing . Samples were conditioned at 20±1 °C and 45, 65, and 85% relative humidity. The calculated ultrasonic longitudinal wave velocity (VLL) was used to determine dynamic MOE (4549 to 4735 MPa) and compared to static MOE (5461 to 5910 MPa). Static MOE values are around 15.3% to 28.1% higher than dynamic values. MOR values, the most influenced properties, decreased from 70.1 MPa to 51.3 MPa with the increase in moisture. Pearson correlation coefficients ranged from 0.52 (MOR vs VLL) to 0.94 MOEdyn vs VLL). The R² values ranged from 0.187 (VLL vs MOR at 85% RH) to 0.94% (VLL vs Edyn at 65% RH).

Anahtar Kelimeler

• Populus x canadensis
• Modulus of rupture
• Modulus of elasticity
• Ultrasound

Kaynakça

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