Thermo-Mechanical Buckling of CFRP Cylindrical Shells with FGPM Coating

In this paper, the buckling behaviors of cylindrical shells made of a new kind of carbon fiber reinforced polymer (CFRP) and coated with functionally graded polymeric material (FGPM) are investigated. The fundamental equations of a moderately-thick shell are established within the framework of Reddy's higher-order shear deformation theory (HSDT). The material model is derived by combining the conventional micro-mechanical CFRP model with the hybrid FGPM model. Micro-crack damage in CFRP core is included via the damage variables. The buckling compressive stresses of the shells exposed to the thermal environment are obtained by the Galerkin's method. The solutions reveal that the lay-up sequence of the laminas and the thickness ratio of the FGPM coating to CFRP core have significant influence on the computed results. The variation of the buckling loads with respect to the content of carbon fiber and distributed profile of the FGPM components follows some nonlinear laws. The structural instability induced by damages appear to be more remarkable with the increased shell thickness. However, this effect can be reduced by optimizing the ply angles of the stacking laminas. More factors, such as geometric parameters, numbers of fiber layers, lamina stacking sequences, damage, material properties and thermal loads, are also discussed in detail.