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http://dx.doi.org/10.12989/scs.2019.30.6.517

Effect of out-of-plane defects on the postbuckling behavior of graphene sheets based on nonlocal elasticity theory  

Soleimani, Ahmad (School of Mechanical Engineering, College of Engineering, University of Tehran)
Dastani, Kia (Department of Mechanical Engineering, Sharif University of Technology)
Hadi, Amin (School of Mechanical Engineering, College of Engineering, University of Tehran)
Naei, Mohamad Hasan (School of Mechanical Engineering, College of Engineering, University of Tehran)
Publication Information
Steel and Composite Structures / v.30, no.6, 2019 , pp. 517-534 More about this Journal
Abstract
In this paper, the effects of inevitable out-of-plane defects on the postbuckling behavior of single-layered graphene sheets (SLGSs) under in-plane loadings are investigated based on nonlocal first order shear deformation theory (FSDT) and von-Karman nonlinear model. A generic imperfection function, which takes the form of the products of hyperbolic and trigonometric functions, is employed to model out-of-plane defects as initial geometrical imperfections of SLGSs. Nonlinear equilibrium equations are derived from the principle of virtual work and variational formulation. The postbuckling equilibrium paths of imperfect graphene sheets (GSs) are presented by solving the governing equations via isogeometric analysis (IGA) and Newton-Raphson iterative method. Finally, the sensitivity of the postbuckling behavior of GS to shape, amplitude, extension on the surface, and location of initial imperfection is studied. Results showed that the small scale and initial imperfection effects on the postbuckling behavior of defective SLGS are important and cannot be ignored.
Keywords
out-of-plane defect; graphene sheet; postbuckling; nonlocal elasticity; first order shear deformation theory; isogeometric analysis;
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