Nonlinear hygrothermal vibration and buckling analysis of imperfect FG-CNTRC cylindrical panels embedded in viscoelastic foundations

This paper investigates the nonlinear free vibration and nonlinear dynamic hygrothermal buckling behavior of imperfect functionally graded carbon nanotube-reinforced composite (FG-CNTRC) cylindrical panels under hygrothermal environment. The nonlinear temperature distribution is assumed along the thickness direction. The structure is resting on a generalized nonlinear viscoelastic foundation which is composed of a two-parameter Winkler-Pasternak foundation augmented by a Kelvin-Voigt viscoelastic model with a nonlinear cubic stiffness and damping considerations. The nonlinear von Kármán strain-displacement relations and the classical shell theory are considered to derive the governing equations of the cylindrical panels. The discretized equations of motion are obtained using the Galerkin method. The fourth order Runge-Kutta method is utilized to analyze the nonlinear dynamic hygrothermal buckling. The influences of the four CNTs distribution types, consist of the FG-O, FG-Λ, FG-X, and UD, are considered for the cylindrical panel. The effects of temperature, moisture, nonlinear viscoelastic foundations, initial imperfection, and material parameters on the nonlinear free vibration and nonlinear dynamic hygrothermal buckling behavior of the system are investigated. •The nonlinear hygrothermal vibration analysis of FG-CNTRC cylindrical panels is presented based on the analytical approach.•The structure is embedded within a generalized nonlinear Kelvin-Voigt viscoelastic foundation.•The nonlinear temperature distribution is assumed along the direction of thickness.•The effect of initial imperfection on the system with four CNTs distributions types is considered.•The natural frequency and the nonlinear dynamic hygrothermal buckling response for the FG−Λ CNTRC is more than others.