Tunç APATAY, Müfit GÜLGEÇ, Ahmet N. ERASLAN

Homojen olmayan malzemeden yapılmış içi dolu dönen disklerin elastik-plastik gerilme analizi

Bu çalışmada, fonksiyonel derecelendirilmiş (FDM) değişken kalınlıklı dönen içi dolu disklerde elastik ve kısmen plastik gerilme durumları için sayısal hesaplamalı bir model geliştirilmiştir. Disk malzemesinin elastisite modülü, Poisson oranı, akma limiti ve yoğunluğu radyal doğrultuda herhangi bir fonksiyon cinsinden değişebilmektedir. Küçük deformasyonlar ve düzlem gerilme durumunun geçerli olduğu kabul edilmiştir. Von Mises kriteri, toplam deformasyon teorisi ve Swift tipinde lineer olmayan bir pekleşme kuralı kullanılarak dönen diskin kısmen plastik davranışını tarif eden bir diferansiyel denklem elde edilmiştir. Bu diferansiyel denklem lineer olmadığı için sayısal çözümü bilgisayar ortamında Newton yinelemeleriyle birleştirilmiş bir shooting metodu kullanılarak elde edilmiştir. Oluşturulan sayısal hesaplamalı model, analitik çözümlerle karşılaştırılarak doğrulanmıştır.

Elastic-plastic stress analysis of nonhomogeneous rotating solid discs

A computational model is developed for the analysis of elastic and partially plastic stress states in functionally graded (FGM) variable thickness rotating solid disks. The modulus of elasticity, Poisson’s ratio, uniaxial yield limit and density of the disk material are assumed to vary radially in any prescribed functional forms. Small deformations and a state of plane stress are presumed. Using the von Mises yield criterion, total deformation theory and a Swift-type nonlinear hardening law, a single nonlinear equation describing elastoplastic behavior of rotating disk is obtained. A shooting technique using Newton iterations with numerically approximated tangents is designed and used for the computer solution of the governing equation. The model is verified by comparing predictions with analytical solutions.

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