Supersonic thermomechanical dynamic instability analysis of imperfect FG-GPLRC conical shell under nonconservative loading

Metallic space structures have gained prominence in recent years owing to their superior hygrothermal behavior in challenging environmental conditions. The present work provides a comprehensive yet simplified geometrically nonlinear thermomechanical stability analysis of functionally graded graphene platelet-reinforced composite (FG-GPLRC) metallic imperfect truncated conical shells (TCSs) under supersonic flow, radial pressure and tangential follower forces. A geometrically nonlinear first-order shear deformable shell formulation is implemented using finite element method taking into account initial imperfection. A nonlinear temperature distribution in the thickness direction of the shell is taken in the analysis of the TCS. The influence of material and loading parameters is investigated with geometric and thermal values pertinent for aerospace structures. The effect of functional gradation and GPL distribution in enhancing the structural stability is shown. The presence of GPL is found to enhance the stability of the structure. Temperature, internal pressure and imperfection are also found to play a significant role in influencing the critical load. With increasing imperfection and internal radial pressure, the critical load increases, whereas it decreases for increasing temperature. The influence of supersonic Mach number and nonlinear amplitude is minimal on the critical load. The dependence of stability on different tangential follower loadings with varied degrees of nonconservativeness is also studied. Both flutter- and divergence-type instability is observed at different parameter regimes.