NUMERICAL INVESTIGATION OF INFLUENCING PARAMETER OF IMPERFECTIONS ON THIN SHORT CARBON STEEL CYLINDRICAL SHELL UNDER AXIAL COMPRESSION

Abstract

Thin cylindrical shell structures have wide variety of applications due to their favorable stiffness-to-mass ratio and under axial compressive loading, these shell structures fail by their buckling instability. Hence, their load carrying capacity is decided by its buckling strength which in turn predominantly depends on the geometrical imperfections present on the shell structure. The main aim of the present study is to determine the more influential geometrical parameter out of two geometrical imperfection parameters namely, "the extent of imperfection present over a surface area" and its "amplitude". To account for these geometrical parameters simultaneously, the imperfection pattern is assumed as a dent having the shape of extent of surface area as a nearly square. The side length of extent of surface area can be considered as proportional to extent of imperfection present over an area and the dent depth can be considered as proportional to amplitude of imperfections. For the present numerical study, FE models of thin short carbon steel perfect cylindrical shells with different sizes of dent are generated at 1/3rd and half the height of cylindrical shells and analyzed using ANSYS nonlinear FE buckling analysis.