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

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کد مقاله : 1015-ISAV2024 (R2)
نویسندگان
1دانشجوی دانشگاه آزاد اسلامی واحد علوم و تحقیقات تهران
2هیات علمی دانشگاه آزاد اسلامی واحد علوم وتحقیقات
3عضو هیات‌ علمی دانشگاه بین المللی امام خمینی (ره)
چکیده
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 nanotube (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 foundation 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
 
Title
Investigating Stiffeners Influence on Stability of Axially -Compressed Metamaterial Sandwich Toroidal Shells Containing Graphene Origami-Enabled Auxetic Core
Authors
Mohammadhossein Goudarzfallahi, Ali Alinia Ziazi, ّFarzad Ebrahimi
Abstract
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 nanotube (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 foundation 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.
Keywords
Stiffeners, graphene origami-reinforced auxetic metamaterial, carbon nanotube-reinforced composite, buckling and post-buckling, toroidal shell segments