Kızılçam odununda (Pinus brutia Ten. ) yorulma özelliklerinin belirlenmesi

Abstract

Bu çalışmada kızılçam (Pinus brutia Ten.) odunundan elde edilen kusursuz küçük örneklerde eğilme direncinin % 30, 40, 50, 60 ve 70 seviyelerinde 5 farklı gerilme, dakikada 15 ve 20 çevrim olmak üzere yorulma yükleri uygulanarak yorulma ömürleri bulunmuştur. Çalışma sonuçlarına göre kusursuz örneklerde %30 ve %40, yükleme seviyelerinde ortalama 1.000.000 üzeri tekrara ulaşmıştır. Genel olarak yükleme seviyesi (S) ile yorulma ömrü (N) arasında ters bir ilişki görülmektedir. Bu ilişki doğrusal olmayan regresyon yöntemiyle modellenmiştir. Log (N) = A * log (S) + B eşitlikleri ile kızılçamda yorulma ömrü tahmin edilebilir. Yorulma testleri uzun sürelerde yapılabildiği için bu çalışmada sadece dakikada 15 ve 20 yükleme kullanılmıştır. Frekansın daha sık ve geniş açıklıklarla uygulanmasıyla kızılçam odununda yorulma davranışı daha iyi anlaşılabilir. Anahtar kelimeler: Kızılçam, Yorulma ömrü, Modelleme

Keywords

• Kızılçam, Yorulma ömrü, Modelleme

Determination of fatigue properties for Turkish red pine (Pinus brutia Ten.)

Abstract

In this study, fatigue strength of red pine (Pinus brutia Ten.) wood was evaluated by applying 15 and 20 cycles per minute and 30% to 70% – 5 different load of static bending strength to small clear wood specimens. The study showed that fatigue life of Turkish red pine wood amounted over 1 million cycles when the stress level was 30 and 40%. In general, there is an inverse relationship between load level (S) and fatigue life (N). This relationship was modeled using nonlinear regression. Fatigue life of red pine wood can be predicted using the equation of Log (N) = A * log (S) + B. Since, fatigue tests are time consuming, only 15 and 20 cycles per minute frequencies were used in the study. By applying more and less frequent loading schemes, the fatigue behavior of red pine wood can be well understood. Keywords: Turkish red pine wood, Fatigue life, Modelling

Keywords

• Turkish red pine wood, Fatigue life, Modelling

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