Nonlinear static/transient behaviors of CNT-reinforced magnetoelectromechanical smart plates and shells considering agglomeration via a dual-director shell model

The application of piezomagnetic layers on the external surfaces of passive sandwich shells has the potential to create multifunctional smart sandwich structures. This work introduces new, smart magnetoelectroelastic (MEE) shells and studies their geometrically nonlinear bending and transient behavior as a first endeavor. A High-order Shear Deformation Theory (HSDT) is adopted to develop the Finite-Element model of the smart MEE shells considering the multiphysics couplings, meanwhile the Lagrangian nonlinear strain–displacement relations are employed to account for the geometric nonlinearity. The developed FE is modeled with nodal degrees of freedom that include displacements, rotations, and electric and magnetic potentials. Moreover, the physical characteristics of aggregated CNTRC are evaluated based on a micromechanics model incorporating the two agglomeration parameters. Different agglomeration schemas are considered for CNTs in the nanocomposite core layer. The precision and reliability of the current FE model are confirmed through a comparison of the existing results in the open literature. The study explores the influence of parameters such as CNT volume fraction and their agglomeration phenomena and various geometrical parameters of the shell on the nonlinear bending and dynamic behavior of smart MEE sandwich structures. The findings provide valuable insights into the subject.