Interaction Between Axisymmetric and Multilobed Creep Buckling of Circular Cylindrical Shells in Axial Compression.

摘要

The present theoretical investigation studies the effect of small multilobed initial deviations from the exact shape upon the deformations and the critical time of a thin-walled circular cylindrical shell which was manufactured with initial axisymmetric deformations. To facilitate the analytical work,the actual solid wall of the shell is imagined to be replaced by an equivalent sandwich wall. The general equilibrium equations derived for shallow shells are expressed in terms of the stresses and deviations corresponding to the equivalent sandwich model. The radial displacement as well as the meridional,circumferential and membrane shear stresses are expressed by finite Fourier series for each face of the sandwich model. A closed form solution is found for the multilobed deformation rates and for the critical time as well. A numerical integration of the deformation rates shows,for a given cylinder,that the multilobed creep buckling deformations grow much faster than the axisymmetric. (Modified author abstract)