Numerical buckling analysis of thin cylindrical shells with combined distributed and local geometrical imperfections under uniform axial compression

In this paper, individual and combined effects of distributed and local geometrical imperfections on the limit load of an isotropic, thin-walled cylindrical shell under axial compression are investigated. First eigen affine mode shape imperfection pattern (FEAMSIP) is taken as distributed geometrical imperfections and dent as local geometrical imperfections. Limit load of the cylindrical shells are determined using non-linear static finite-element analysis module of general purpose FE software ANSYS. A parametric study on the effect of both imperfection patterns is done by varying the size and orientation of the dent. From the numerical results obtained, it is found that distributed geometrical imperfections namely, FEAMSIP have more influence on buckling strength than local geometrical imperfections namely dent.