Mechanical behavior of wood under torsional and tensile loadings

Ağaç ve ağaç ürünleri önemli yapı malzemeleri arasında bulunmaktadır. Günümüzde, tasarımcılar ağaç yapı tasarımlarını; mühendislik prensipleri içerisinde gerçekleştirmeyi öğrendiler. Böylece, yapısal tasarımcılar kullandıkları malzemelerin özelliklerini ve davranışlarını bilmek zorundadırlar. Ağacın özellikleri ve davranışları, onların organik yapılarını dikkate aldığımızda, diğer malzemelerden oldukça farklı ve karmaşıktır. Bu çalışmada, çekme ve burulma deneyleri, Türkiyedeki kayın, çam ve meşe ağaçlarının mekanik davranışlarını incelemek için yapılmıştır. Çalışma sırasında ağaç, yanal ortotropik fiber yapılı kompozit olarak değerlendirilmiştir. Gerilme-genleme grafikleri, eğer varsa elastik ve plastik bölgeleri, akma noktalarını ve ek olarak fiber kompozit elastik malzeme sabitlerini bulmak için oluşturularak incelenmiştir. Sonuçlar yaklaşık hata oranları arasında elde edilmiştir. Araştırmanın sonunda ise, gerilme boşalması testleri çam ve kayın ağaçlarının üzerinde burulma yüklemesi altında test edilmiştir.

Burulma ve çekme yüklemeleri altında ağacın mekanik davranışları

Wood and wood products are among important construction materials. More recently, designers have learned to design wood structures in ways that are based on engineering principles. In doing this, a structural designer must be familiar with the properties and behavior of the material. The properties and behavior of wood are unlike those for other materials and much more complex by considering their organic structure. In this study, torsion and tensile tests were performed in order to examine the mechanical behaviors of Turkish beech, pine and oak woods. In doing this, wood is considered as a transversely isotropic fiber composite material. The stress-strain curves were constituted and examined in order to show the elastic and plastic regions, the.yield points if they are exist and additionally fiber composite elastic material constants of them. They were determined within the approximate error ranges. At the end of the research, stress relaxation tests were applied on both pine and beech woods under torsion loadings.

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