Thermo-torsional postbuckling of CNT-reinforced composite toroidal shell segments with surrounding elastic media and tangentially restrained edges

Abstract

An analytical investigation on the nonlinear stability of toroidal shell segment (TSS) made of carbon nanotube (CNT)-reinforced composite, surrounded by an elastic medium, exposed to elevated temperature and subjected to uniform torsion is presented in this paper. The properties of constituents are assumed to be temperature dependent and effective properties of composite are determined using an extended rule of mixture. CNTs are embedded into matrix phase according to functionally graded or uniform distributions. Basic equations in terms of deflection and stress function are established within the framework of classical shell theory including geometrical nonlinearity in von Kármán–Donnell sense and interactive pressure from surrounding elastic medium. Two boundary edges of the shell are assumed to be simply supported and tangentially restrained. Multi-term analytical solutions are assumed and Galerkin method is used to derive expressions of buckling load and nonlinear relation between torsional load and deflection. Parametric studies are carried out to analyze the effects of material and geometry properties, in-plane boundary condition, elevated temperature and surrounding elastic medium on the buckling resistance and postbuckling behavior of torsionally loaded TSS. Novel finding of this study is that tangential edge constraints have no and negative effects on critical torsional loads at room and elevated temperatures, respectively, and profoundly beneficial influences on postbuckling load capacity of TSSs.

Thermoelastic nonlinear vibration and dynamical response of geometrically imperfect carbon nanotube-reinforced composite plates on elastic foundations including tangential edge constraints

“…The effects of tangentially elastic constraints of boundary edges on the nonlinear stability of functionally graded ceramic-metal and CNT-reinforced plates and shells have been addressed in analytical works of Tung and coworkers. [52][53][54][55][56][57][58] To the best of authors' knowledge, there is no investigation on the nonlinear vibration of FG-CNTRC plates with tangentially restrained edges in the literature.…”

Nonlinear thermo-elastic stability of corrugated-core toroidal shell segments with carbon nanotube-reinforced face sheets under radial pressure

“…15,16 Similar to the FGM, the buckling, post-buckling, free vibration, and static analysis of CNTreinforced cylindrical shells, shell panels, and toroidal shell segments were also given due attention. [12][13][14][17][18][19][20] The interesting effects of CNT on the mechanical behavior of cylindrical shells were investigated and discussed in detail. Snap-through behavior, thermal and inertial buckling, vibration, and wave propagation of CNT-reinforced beams were investigated using different theories and methods.…”