Hygrothermal effects on the postbuckling of composite laminated cylindrical shells

The influence of hygrothermal effects on the buckling and post-buckling of composite laminated cylindrical shells subjected to combined loading of external pressure and axial compression has been investigated by using a micro-to-macro-mechanical analytical model. The material properties of the composite are affected by the variation of temperature and moisture, and are based on a micro-mechanical model of a laminate. The governing equations are based on the classical laminated-shell theory, including hygrothermal effects. The non-linear prebuckling deformations and initial geometric imperfections of the shell are both taken into account. A boundary layer theory of shell buckling is extended to the case of laminated cylindrical shells under hygrothermal environments and a singular perturbation technique is employed to determine the interactive buckling loads and post-buckling equilibrium paths. The numerical illustrations concern the post-buckling behaviour of perfect and imperfect, cross-ply laminated cylindrical shells under different sets of environmental conditions. The results show that the hygrothermal environment has a significant effect on the interactive buckling load as well as post-buckling response of the shell. In contrast, it has a small effect on the imperfection sensitivity.