Dynamic analysis of piezolaminated shell structures reinforced with agglomerated carbon nanotubes using an enhanced solid-shell element

This work introduces a linear dynamic analysis of composite smart solid-shell structures reinforced with agglomerated Carbone Nanotubes and embedded at external faces with piezolayers. The coupled electro-mechanical governing equation of solid-shell structures under dynamic loads is obtained by the estimation of the displacement field with the First-Order Shear Deformation Theory (FSDT). In this proposed model, the shear and thickness locking were solved by the use of the Assumed Natural Strain (ANS) method as well as the Enhanced Assumed Strain (EAS) method is adopted for enhancing of the membrane and transversal strains. Each element of the structure is modeled by an eight-node hexahedron with four degrees of freedom: three displacements and an electrical potential. The middle part of the structure is made of a composite reinforced with agglomerated Carbone Nanotubes (CNTs) along the thickness. Different agglomeration schemes are investigated by means of a two-parameter agglomeration model. The external faces of the shell structure are made with piezoelectric material which accentuates the smart aspect of such structures. The mechanical properties of such a reinforced composite are evaluated using Mori-Tanaka (EMT)'s technique. An enhanced finite-element solid-shell model is implemented to investigate the effects of nanotubes agglomeration on the transient response of solid shells, such as the impact of various configurations of agglomerations, the volume fraction of CNTs, and some geometrical parameters of solid-shell structures. From deduced numerical results, it is exposed that the reinforcing fibers with different agglomeration schemes retain a significant impact on the dynamic performances of the solid-shell structure.