Postbuckling of axially loaded FGM hybrid cylindrical shells in thermal environments

Abstract

A postbuckling analysis is presented for a functionally graded cylindrical shell with piezoelectric actuators subjected to axial compression combined with electric loads in thermal environments. Heat conduction and temperature-dependent material properties are both taken into account. The temperature field considered is assumed to be a uniform distribution over the shell surface and varied in the thickness direction and the electric field is assumed to be the transverse component E Z only. The material properties of functionally graded materials (FGMs) are assumed to be graded in the thickness direction according to a simple power law distribution in terms of the volume fractions of the constituents, and the material properties of both FGM and piezoelectric layers are assumed to be temperature dependent. The governing equations are based on a higher order shear deformation theory with a von Kármán-Donnell-type of kinematic nonlinearity. A boundary layer theory of shell buckling is extended to the case of FGM hybrid laminated cylindrical shells of finite length. A singular perturbation technique is employed to determine the buckling load and postbuckling equilibrium paths. The numerical illustrations concern the postbuckling behavior of axially loaded, perfect and imperfect, FGM cylindrical shells with fully covered piezoelectric actuators under different sets of thermal and electric loading conditions. The results reveal that temperature dependency, temperature change and volume fraction distribution have a significant effect on the buckling load and postbuckling behavior of FGM hybrid cylindrical shells. In contrast, the control voltage has a very small effect on the buckling load and postbuckling behavior, and it has almost no effect on the imperfection sensitivity of the FGM hybrid cylindrical shells.