Influence of localized imperfection on the instability of isotropic/cross-ply cylindrical shells/rings under external pressure

Effects of thickness and fibre misalignment on compression fracture in cross-ply (very) long cylindrical shells under external pressure

“…The elastic post-buckling response of relatively thin isotropic or laminated arch/ring/shelltype structures under external pressure, which is known to be primarily characterized by the stability or loss thereof of equilibrium at the macrostructural level, has been extensively studied during the past few decades (see [27][28][29] and citations therein). The buckled states of an externally pressurized cylindrical shell are characterized by a cellular shape in the circumferential direction with a large azimuthal number [30][31][32]. The influence of localized imperfections on the elastic buckling of a long cylindrical shell (with large Batdorf parameter) under axial compression, by using a double scale analysis including interaction modes, has been investigated by Hunt & Lucena Neto [33] and Jamal et al [34].…”

“…The buckled states of an externally pressurized cylindrical shell are characterized by a cellular shape in the circumferential direction with a large azimuthal number [30][31][32]. The influence of localized imperfections on the elastic buckling of a long cylindrical shell (with large Batdorf parameter) under axial compression, by using a double scale analysis including interaction modes, has been investigated by Hunt & Lucena Neto [33] and Jamal et al [34].…”

“…Kim & Chaudhuri [35] have investigated the role of lamination sequence, in conjunction with modal imperfection in lowering the load-carrying capability of infinitely long thick laminated cross-ply cylindrical shells (plane strain rings) with linear material property. The appearance of a limit point on the elastic post-buckling equilibrium path has been found to be a measure of the effect of interlaminar shear/normal deformation on localization [31,35,36].…”

“…Compressive response of two extreme cases of cylindrical shell-type structures weakened by the presence of localized imperfections has been investigated by Kim & Chaudhuri [31]. These two extreme cases are (i) thin metallic cylindrical shells, which are characterized by the previously mentioned cellular shape in the circumferential direction with a large azimuthal number, and (ii) thick laminated advanced fibre reinforced composite rings (very long cylindrical shells), whose response is dominated by the interlaminar or transverse (primarily shear) deformation.…”

“…These complexities and uncertainties relate to very fundamental questions pertaining to (i) linkage between macrostructural instability, such as buckling/postbuckling failure of a structural component, e.g. a ring or cylindrical shell at the geometric scale of at least several centimetres and larger [11,31,32,[35][36][37], and microstructural instability, such as kink band type failure at the fibre-matrix level (at the geometric scale of about 10 µm) investigated by Chaudhuri & Garala [10], Chaudhuri et al [12], Chaudhuri [6], Moran et al [38], Moran & Shih [39], Gutkin et al [40] and others. The nonlinear finite-element analysis (FEA) results [11,31,32,[35][36][37][41][42][43] pertaining to the appearance of a limit point on the equilibrium path that results in localization of the deformation pattern in and lowering of the load-carrying capability of laminated carbon/epoxy composite cylindrical shells and rings, demonstrate their extreme sensitivity to thickness shear, modal/local geometric imperfections as well as material nonlinearity ('yield' stress and strain hardening).…”