In this work, the stress-driven method (SDM) was used to investigate the
axisymmetric nonlinear vibrational behavior of functionally graded circular
nanoplates and the results were compared with those of strain gradient theory
(SGT). The governing equations and related boundary conditions were derived
using Hamilton’s principle based on the SDM and SGT. Then, the governing
equations and related boundary conditions were discretized and solved using
the generalized differential quadrature rule (GDQR) in conjunction with
the Galerkin weighted residual method (GWRM). The results of this study
have been compared and validated with the results of other studies when
applicable. The effects of aspect ratio, different boundary conditions, and mode
number on the overall behavior of the nanoplates were investigated. The
results show that considering the small-scale effect will have a significant
influence on the results. Also, the comparison of linear and nonlinear behavior
confirms the importance of using nonlinear behavior. Based on the SDM and
SGT results, any increase in the magnitude of the material size parameter
results in
a decrease in the frequency ratios in all modes for all types of boundary conditions
mentioned above. The maximum decrease results from the SGT model. In addition, the
differences between the SDM and SGT frequency ratios increase as the material size
parameter
increases. Increasing the values of the aspect ratio
increases the frequency ratios in all modes for all types of boundary conditions. This
result appears to be valid for all selected values of the material size parameter
.
Furthermore, for any specific value of the initial condition
and
the material size parameter, the smallest and largest frequency ratios are related to
the SGT and SDM, respectively.