A novel approach for steady-state creep analysis of thick-walled cylindrical pressure vessels

چکیده مقاله

The goal of this study is to provide a new method for solving the steady-state creep of thick-walled cylindrical pressure vessels. For this purpose by using an analytical approach, the elastic and steady-state creep problems of the thick-walled structures is investigated. The radial, tangential and effective stresses for the elastic and creep solutions are obtained separately and the total stresses considered as the sum of elastic and creep stresses. We supposed that the rate of creep strains in the second stage of creep was according to Norton’s law. Also the relationship of multiaxial stress and the rate of strains is represented by Prandtl-Reuss equations. To determine the unknown constants of creep stresses in thick walled structures, boundary conditions can be considered as the stress rates. The cylindrical vessel supposed to have open ends and long length, so the analytical solution is obtained for the plane strain and plane stress conditions. The validity of proposed method for the steady state creep solution was checked with the time dependent method from literature. According to the obtained results, the enhanced steady-state analysis can be used to predict the creep behavior of thick-walled structures for a long time.