Influence of density on Mode I fracture behavior of southern yellow pine (Pinus taeda L.) wood

Abstract

This study aimed to investigate the influence of density on the fracture behavior of southern yellow pine (Pinus taeda L.) wood in radial-longitudinal crack propagation direction under mode I loading. The density of the crack-tip location for each fracture test block was determined by using an X-ray density profile analyzer. Three fracture parameters were obtained from the load-deformation curve of each fracture test block, namely fracture toughness, initial slope, and specific fracture energy. In general, the results showed that the fracture parameters were strongly influenced by the density. Crack-tip locations with higher density were found to be more resistant to crack initiation. The initial slope of the load-deformation curve increased as the crack density in the wood increased. As a result of the regression analysis, it was observed that there were positive and strong correlations between density and each fracture parameter.

Keywords

• Fracture
• Fracture toughness
• Southern yellow pine
• Specific fracture energy
• Initial slope

Yoğunluğun güney sarıçam (Pinus taeda L.) ağacının Mod I kırılma davranışı üzerine etkisi

Abstract

Bu çalışma, güney sarıçam (Pinus taeda L.) odununun mod I yüklemesi altında radyal-boyuna çatlak ilerleme yönünde kırılma davranışına yoğunluğun etkisini araştırmayı amaçlamıştır. Her bir kırılma testi bloğu için çatlak ucu konumunun yoğunluğu, X-ışını yoğunluk profili analizörü kullanılarak belirlenmiştir. Her bir kırılma test bloğunun yük-deformasyon eğrisinden başlangıç eğimi, kırılma tokluğu ve özgül kırılma enerjisi olmak üzere üç kırılma parametresi elde edilmiştir. Genel olarak, sonuçlar kırılma parametrelerinin yoğunluktan güçlü bir şekilde etkilendiğini göstermiştir. Yüksek yoğunluğa sahip çatlak ucu konumları, çatlak başlangıcına karşı daha dirençli görülmüştür. Yük-deformasyon eğrisinin ilk eğimi, ahşaptaki çatlak yoğunluğu arttıkça artmıştır. Regresyon analizi sonucunda yoğunluk ile her bir kırılma parametresi arasında pozitif ve güçlü korelasyonların olduğu gözlemlenmiştir.

Keywords

• Kırılma
• Kırılma tokluğu
• Güney sarıçam
• Özgül kırılma enerjisi
• Başlangıç eğimi

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