Free and forced vibrations of functionally graded polymer composite plates reinforced with graphene nanoplatelets

Free vibration and elastic buckling of functionally graded porous beams reinforced by graphene platelets

The review outlines modern trends in theoretical developments, novel designs and modern applications of sandwich structures. The most recent work published at the time of writing of this review is considered, older sources are listed only on as-needed basis. The review begins with the discussion on the analytical models and methods of analysis of sandwich structures as well as representative problems utilizing or comparing these models. Novel designs of sandwich structures is further elucidated concentrating on miscellaneous cores, introduction of nanotubes and smart materials in the elements of a sandwich structure as well as using functionally graded designs. Examples of problems experienced by developers and designers of sandwich structures, including typical damage, response under miscellaneous loads, environmental effects and fire are considered. Sample applications of sandwich structures included in the review concentrate on aerospace, civil and marine engineering, electronics and biomedical areas. Finally, the authors suggest a list of areas where they envision a pressing need in further research.

Review of current trends in research and applications of sandwich structures

https://espace.library.uq.edu.au/view/UQ:415632/UQ415632_OA.pdf

Buckling and postbuckling of functionally graded multilayer graphene platelet-reinforced composite beams

This paper studies the nonlinear bending behavior of a novel class of multi-layer polymer nanocomposite beams reinforced with graphene platelets (GPLs) that are non-uniformly distributed along the thickness direction. Nonlinear governing equation is established based on Timoshenko beam theory and von Karman nonlinear strain-displacement relationship. The effective Young's modulus of the nanocomposites is determined by modified Halpin-Tsai micromechanics model. Ritz method is employed to reduce the governing differential equation into an algebraic system from which the static bending solutions can be obtained. A comprehensive parametric study is then conducted, with a particular focus on the influences of distribution pattern, weight fraction, geometry and size of GPLs together with the total number of layers on the linear and nonlinear bending performances of the beams. Numerical results demonstrate the significantly improved bending performance through the addition of a very small amount of GPLs into polymer matrix as reinforcements. It is found that dispersing more GPLs that are in square shape with fewer single graphene layers near the top and bottom surfaces of the beam is the most effective way to reduce bending deflections. Beams with a higher weight fraction of GPLs that are symmetrically distributed in such a way are also less sensitive to the nonlinear deformation.

Nonlinear bending of polymer nanocomposite beams reinforced with non-uniformly distributed graphene platelets (GPLs)

https://espace.library.uq.edu.au/view/UQ:416842/UQ416842_OA.pdf

Dynamic instability of functionally graded multilayer graphene nanocomposite beams in thermal environment

https://espace.library.uq.edu.au/view/UQ:676408/UQ676408_OA.pdf

Thermal buckling and postbuckling of functionally graded graphene nanocomposite plates

The nonlinear vibration of imperfect shear deformable functionally graded carbon nanotube-reinforced composite (FG-CNTRC) beams is studied in this paper based on the first-order shear deformation beam theory and von Karman geometric nonlinearity. A one-dimensional imperfection model in the form of the product of trigonometric and hyperbolic functions are used to describe the various possible geometric imperfections such as sine type, global, and localized imperfections. The governing equations are derived by employing the Ritz method and then solved by an iteration procedure. Special attention is given to the influences of imperfection mode, location, and amplitude on the nonlinear behaviour. The linear vibration is also discussed as a subset problem. Numerical results in tabular and graphical forms show that the nonlinear vibration behaviour of imperfect FG-CNTRC beams is considerably sensitive to sine type and global imperfections (except for G2-mode), whereas the effect of localized imperfection is much less pronounced. It is also observed that whether the FG-CNTRC beam exhibits the “hard-spring” or “soft-spring” vibration behaviour is largely dependent on the initial imperfection mode, its amplitude as well as the vibration amplitude.

/pdf/nonlinear-vibration-of-functionally-graded-carbon-nanotube-4rdh70vlol.pdf

Nonlinear vibration of functionally graded carbon nanotube-reinforced composite beams with geometric imperfections

https://espace.library.uq.edu.au/view/UQ:705420/UQ705420_OA.pdf

Helong Wu

Papers

Buckling and postbuckling of functionally graded multilayer graphene platelet-reinforced composite beams

Dynamic instability of functionally graded multilayer graphene nanocomposite beams in thermal environment

Thermal buckling and postbuckling of functionally graded graphene nanocomposite plates

Nonlinear vibration of functionally graded carbon nanotube-reinforced composite beams with geometric imperfections

Parametric instability of thermo-mechanically loaded functionally graded graphene reinforced nanocomposite plates