Nonlinear Postbuckling of Auxetic-Core Sandwich Toroidal Shell Segments with CNT-Reinforced Face Sheets Under External Pressure

Abstract

Nonlinear buckling analysis for honeycomb auxetic-core sandwich toroidal shell segments with CNT-reinforced face sheets surrounded by elastic foundations under the radial pressure is presented in this study. The basic equation system of shells is established based on the von Kármán–Donnell nonlinear shell theory, combined with Stein and McElman approximation. Meanwhile, the foundation-shell elastic interaction is simulated by the foundation model based on the Pasternak assumption. The Galerkin procedure is utilized to achieve the pre-buckling and post-buckling responses for the shell, from which the radially critical buckling load is determined. Numerical analysis shows the various influences of auxetic-core layer, CNT-reinforced face sheets, and elastic foundation on the pre-buckling and postbuckling behavior of sandwich shells with CNT reinforced face sheets.

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

“…The deflection of the shell satisfying the simply supported boundary condition is modeled in the average form, as 20,41 wðx, yÞ…”

“…The deflection of the shell satisfying the simply supported boundary condition is modeled in the average form, as 20,41 where m and n are the positive integer numbers that present the buckling modes of the shells.…”

“…The geometrically nonlinear Donnell shell theory is employed to formulate the basic equation system of buckling responses of corrugated-core toroidal shell segments. The nonlinear forms between the mid-plane strains normalεx0, normalεy0 and normalγxy0, and the displacements u,v, and w can be presented as 20,41 …”

“…38,39 In addition, CNTreinforced composites can also be designed as face sheets and combined with auxetic cores to increase the bearing capacity of the cylindrical shells and toroidal shell segments. [40][41][42] Some works on the viscoelastic behavior of CNT-reinforced cylindrical shells subjected to earthquake loads were also performed taking into account the thermal and moisture effects. 43,44 The CNT-reinforced composite was also designed as a type of laminated composite and the effects of negative Poisson's ratio were investigated.…”

Nonlinear buckling responses of radially pressured FG-GPLRC toroidal shell segments

“…The linear buckling and vibration of shear deformable FG-GPLRC cylindrical shells with eccentric rotating were also investigated [9]. For toroidal shell segments, the nonlinear thermomechanical and mechanical buckling problems of FG-CNTRC shells and FG-CNTRC shells with auxetic core were mentioned using the Donnell shell theory and Galerkin method [10,11].…”