Investigating Stiffeners Influence on Stability of Axially -Compressed Metamaterial Sandwich Toroidal Shells Containing Graphene Origami-Enabled Auxetic Core(ISAV۲۰۲۴)

This study examines the buckling and post-buckling behavior of stiffened sandwich toroidal shell segments (TSSs) with a graphene origami (GOri)-enabled auxetic core and carbon nano-tube (CNT)-reinforced face sheets supported by elastic foundations under axial compression. The TSSs are stiffened with CNT-reinforced stringers or rings, modeled using a novel smeared stiffener technique. CNTs are distributed uniformly (UD) or functionally graded (FG) across the face sheets and stiffeners. Nonlinear equilibrium equations are derived using von Kármán shell theory and Stein and McElman approximations, with a Winkler-Pasternak elastic foun-dation considered for shell-foundation interactions. The Galerkin method is used to solve the nonlinear load-deflection relationship, which is then applied to calculate buckling loads and analyze post-buckling behavior. Numerical investigations focus on the effects of stiffeners, CNT volume fraction, and distribution types on the buckling and post-buckling behavior of auxetic-core TSSs, confirming that stiffeners substantially enhance the critical buckling loads and post-buckling strength.

کلیدواژه ها:

stiffeners ، auxetic core ، buckling and post-buckling ، toroidal shells