NONLINEAR DYNAMIC STABILITY OF FUNCTIONALLY GRADED SHELLS SUBJECTED TO THERMAL ENVIRONMENT
This paper highlights the nonlinear dynamic stability characteristics of functionally graded (FG) shell panels subjected to thermal gradient using the finite element approach. Properties of FG materials are assumed to be temperature dependent and graded in the thickness direction. Two shell forms, viz., singly curved cylindrical (CYL) and doubly curved spherical (SPH) shell panels are considered in the present analysis. The theoretical formulation considers Sanders’ approximation for doubly curved shells and von Kármán type nonlinear strains are incorporated into the first order shear deformation theory (FSDT). The in-plane periodic load is taken as the parametric excitation in the governing equation. The nonlinear matrix amplitude equation is obtained by employing the Galerkin’s method. The structural system is considered to be undamped. Effects of material composition and geometrical parameters are studied on the nonlinear dynamic stability characteristics of the above-mentioned two forms of shell panels.