ABSTRACT
The purpose of this work is to investigate the static behavior of piezolaminated thin-walled functionally graded material (FGM) and composite shells in the range of geometrically linear and nonlinear deformations. A power law type variation of FGM material properties is adopted. Finite rotations and full nonlinear terms in the geometrically nonlinear strain-displacement relations are considered in the framework of FOSD theory to derive the variational formulation. In order to enrich the behavior and reliability of the four-node piezolaminated composite shell element, an assumed natural strain (ANS) method for the shear strains, an enhanced assumed strain (EAS) method for the membrane strains and an enhanced assumed gradient (EAG) method for the electric field is encompassed. Predictive capabilities of the proposed numerical formulation are demonstrated using several numerical examples, in particular shells integrated with piezolayers in both sensory and actuator applications in the range of linear and geometrically nonlinear deformations. Numerical simulations with the present model and other simplified nonlinear models available in literature are performed and compared, demonstrating the worthiness of the present method in large deflection analysis. Additionally, the present results are compared with those obtained by Abaqus by modeling the master structure using the shell S8R element and piezo-layers using C3D20RE solid elements.
