The Collapse of Composite Cylindrical Panels with Various Thickness using Finite Element Analysis

This study compared numerical collapse results of graphite-epoxy cylindrical panels with free vertical edges undergoing axial compression for three different shell theories. Symmetric quasi-isotropic laminates were investigated using solid panels and panels with five different centralized cutouts with three thicknesses. The theories compared in the study were the Simplified Large displacement moderate Rotation (SLR) theory, the Donnell Cylindrical Shell (Modified Donnell) theory, and the Classical Donnell theory. The purpose of the study was to determine when large rotations and through-the-thickness shear become important in the numerical collapse analysis of cylindrical composite shells. By observing cases where the numerical collapse results for each of the three theories differed noticeably (\u3e3%), it could be determined when large rotations and through-the-thickness shear were important. The effects of large rotations were noticed in nearly all of the panels with large cutouts (\u3e3% panel area). Large rotations were also found to be important for thicker panels with either no cutout or a small cutout. The effects of through-the-thickness shear were only noticed in the thickest panels with large cutouts