Çelik tencerelerde taban olarak bakır (Cu) veya alüminyum (Al) kullanılması durumunda gerilme ve şekil değişimlerinin incelenmesi

Katmanlı bir yapıda, metal plakanın bir tarafı düzensiz olarak ısıtılırken diğer tarafında düzgün bir sıcaklık dağılımına ulaşmak istendiğinde ( çakma tabanlı tencerelerde olduğu gibi) katmanlı yapının kalınlıkları üzerinde bir düzenlemeye gitmek gerekir. Isıl genleşme katsayıları farklı, iki malzemeden oluşmuş bir katmanlı silindirik yapının, ortaya çıkacak sıcaklık değişimlerinde farklı genleşme göstermesi de üzerinde çalışılması gereken önemli bir problemdir. Bu çalışmada, bu ana fikir etrafında bu probleme çözüm arandı. Bu amaçla katmanlı yapının ısıtılan tarafına değişen kalınlıklarda Cu/Al yerleştirildi. Al/CrNi katmanlı yapısı Cu/CrNi katmanlı yapısına göre daha düşük ısı iletimi ve daha yüksek sıcaklık gradyenti gösterdi. İki farklı metalin arayüzeyindeki ısıl gerilmeler de imalatçının dikkatine sunuldu. Simülasyon sonucunda Cu/CrNi katmanlı yapısında Al/CrNi katmanlı yapısına göre daha düzgün bir sıcaklık dağılımı ve daha düşük gerilme değerleri ortaya çıktığı gözlendi. Bu amaç için sonlu elemanlar yöntemi (FEM) program paketi; ANSYS kullanıldı.

An investigation of changing stress and shape in a copper and aluminium layered base of a steel saucepan

In order to get the benefits of a multilayered structure when a regular temperature distribution is required on one side of a metal plate with an other side heated irregularly to be layered plate (i.e. in the cases of cooking soucepans etc.), regulation between the thicknesses of the layered structure is needed. A layered cylindrical structure which is manufactured from two materials with different thermal expansion coefficients, shows various expansion with temperature. This also forms an important problem that should be investigated. In this study, the main idea has been finding a solution to the problem of non-regular distribution of temperature on the nonheated side of an irregularly heated plate by means of placing two layers of Cu/CrNi and Al/CrNi of varying thicknesses in a combined, structure. Al/CrNi laminated plate has a low temperature gradient distribution on the upper (or nonheated) surface due to its lesser heat conductivity compared to the Cu/CrNi steel. The thermal stress in the interface of two different materials has been point out to the care of the manufacturers. Simulation results show that layered structure of Cu/CrNi produced a better distrubition of temperature and thermal stresses at the unheated side of the metal plate. For this aim, Finite Elements Method (FEM) program package ANSYS has been used.

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