The effects of hygrothermal conditions on the postbuckling of shear deformable laminated cylindrical shells

The effect of hygrothermal conditions on the buckling and postbuckling of s hear deformable laminated cylindrical shells subjected to combined loading of axial compression and external pressure is investigated using a micro-to -macromechanical analytical model. The material properties of the composite are affected by the variation of temperature and moisture, and are based o n a micro-mechanical model of a laminate. The governing equations are based on Reddy's higher order shear deformation shell theory with von Karman-Don nell-type of kinematic nonlinearity and including hygrothermal effects. The nonlinear prebuckling deformations and initial geometric imperfections of the shell are both taken into account. A boundary layer theory of shell buc kling is extended to the case of shear deformable laminated cylindrical she lls under hygrothermal environments and a singular perturbation technique i s employed to determine the interactive buckling loads and postbuckling equ ilibrium paths. The numerical illustrations concern the postbuckling behavi our of perfect and imperfect, moderately thick, cross-ply laminated cylindr ical shells under different sets of environmental conditions. The results s how that the hygrothermal environment has a significant effect on the inter active buckling load as well as postbuckling response of the shell. In cont rast, it has a small effect on the imperfection sensitivity of the shell wi th a very small geometric imperfection. (C) 2001 Elsevier Science Ltd. All rights reserved.