Agglomeration effects on the vibrations of CNTs/fiber/polymer/metal hybrid laminates cylindrical shell

This work studies the agglomeration effect of continuously graded single-walled carbon nanotubes (SWCNTs) on the vibration of SWCNTs/fiber/polymer/metal laminates cylindrical shell. The strain-displacement relations are applied according to the Kirchhoff Love's first approximation shell theory, whereas the dimensionless frequencies of the structure are obtained by means of the beam modal function model. Fiber, carbon nanotubes (CNTs), polymer matrix and metal are four phases constituting the agglomerated CNTs/fiber/polymer/metal laminate (CNTFPML) cylindrical shell. In the first step, we introduce the CNTs randomly within the matrix, such that the volume fraction can be assumed to be continuously graded in the thickness direction. We determine the effect of the CNTs agglomeration on the elastic properties of CNT-reinforced composites, by means of the Eshelby-Mori-Tanaka approach here applied on an equivalent fiber. In the second step, the fiber is introduced as reinforcement phase in the CNT-reinforced composite. Finally, the adhesive fiber prepreg is combined with the thin metal layers. Thus, we study the sensitivity of the vibration behavior of the cylindrical shell to the following input parameters, namely: the CNTs agglomeration and distribution, the mass and volume fractions of the fiber, the boundary condition and lay-ups.