Numerical modeling of stresses and buckling loads of isogrid lattice composite structure cylinders

Isogrid composite lattice cylindrical structure with or without skins which consists of a system of ± (with respect to the shell axis) helical ribs and circumferential ribs, and has no skins or has skins was studied in a numerical method using ANSYS software, where in this model axial compression and/or pressure loads are applied, to determine the different failure modes which are, failure due to stress exceeds material strength, failure due to local buckling of ribs (crippling), failure due to general buckling of the cylinder and failure due to local buckling skin if the skin is existed. An example was studied to compare the results obtained from the numerical method and other research article.