Finite Element Analysis of Buckling of Thin Cylindrical Shell Subjected to Uniform External Pressure

Abstractone of the common failure modes of thin cylindrical shell subjected external pressure is buckling.the buckling pressure of these shell structures are dominantly affected by the geometricalimperfections present in the cylindrical shell which are very difficult to alleviate duringmanufacturing process. in this work, only three types of geometrical imperfection patterns areconsidered namely (a) eigen affine mode imperfection pattern, (b) inward half lobe axisymmetricimperfection pattern extended throughout the height of the cylindrical shell and (c) localgeometrical imperfection patterns such as inward dimple with varying wave lengths located at themid-height of the cylindrical shell. ansys fe non-linear buckling analysis including bothmaterial and geometrical non-linearities is used to determine the critical buckling pressure. fromthe analysis it is found that when the maximum amplitude of imperfections is 1t, the eigen affineimperfection pattern gives out the lowest critical buckling pressure when compared to the otherimperfection patterns considered. when the amplitude of imperfections is above 1t, the inner halflobe axisymmetric imperfection pattern gives out the lowest critical buckling pressure whencompared to the other imperfection patterns considered.