異方性多層厚肉回転対称殻のクリープ変形

抄録

The paper describes an analytical formulation and a numerical solution of the creep problems of anisotropic multi-layered moderately thick shells of revolution whit application to a cylindrical shell. The analytical formulation is developed by extending the Reissner-Naghdi theory for elastic shells with consideration given to the effect of shear deformation. For the constitutive relation, Hooke's law for orthotropic materials is used in the elastic deformation, and equations based on the orthotropic creep theory derived from the orthotropic plastic theory by Hill are employed in the creep range. The creep strains are related to the stresses by McVetty's equation having the thermal effect multiplier by Arrhenius. The basic differential equations derived are numerically solved by a finite difference method. As a numerical example, the creep of a two-layerd, anisotropic cylindrical shell composed of mild steel and stainless steel subjected to uniform internal pressure is analyzed. Numerical computations have been carried out for four cases of the combinations of the directions of the anisotropic principal axis. It is found from the computations that the internal force distributions and the deformation are significantly varied depending on the combinations of the directions in layers.