Postbuckling analysis of smart FG-CNTRC annular sector plates with surface-bonded piezoelectric layers using generalized differential quadrature method

The purpose of the present study is to introduce the application of carbon nanotubes (CNTs) and piezoelectric layers in suppressing the postbuckling deflection of functionally graded carbon nanotube reinforced composite (FG-CNTRC) annular sector plates. To achieve this objective, a structural model is developed based on the first-order shear deformation theory (FSDT) along with the von Karman geometrical nonlinearity. The distribution of electric potential across the thickness of piezoelectric layers is modeled by a combination of linear and sinusoidal functions and the closed circuit electrical boundary condition is taken into account for the top and bottom surfaces of the piezoelectric layers. Generalized differential quadrature method (GDQM) is implemented to discretize the nonlinear stability equations, boundary conditions and Maxwell equation. The nonlinear system of equations is solved via a direct iterative method. A detailed parametric study is conducted to explore effects of geometrical parameters, boundary conditions, piezoelectric materials, thickness of the piezoelectric layers, external electric voltage, CNT distribution, and volume fraction on the postbuckling responses of FG-CNTRC annular sector plates with surface-bonded piezoelectric layers. Results indicate that both volume fraction and distribution of CNTs play a key role in enhancing the postbuckling strength of CNTRC annular sector plates. It is found that the type of piezoelectric materials, thickness of piezoelectric layers and the external electric voltage have a significant effect on suppressing the postbuckling deflection of FG-CNTRC annular sector plates. It is also found that the distribution of CNTs plays a pivotal role in changing buckling mode shapes of CNTRC annular sector plates. Besides, the proposed solution procedure has shown clear advantages over existing methods and demonstrated itself as a general, stable and accurate numerical method in solving strongly coupled nonlinear partial differential equations.