Nonlinear eigenfrequency characteristics of multi-directional functionally graded porous panels

The eigenfrequency characteristics of the doubly-curved FG panel are examined in the present article considering multi-directional grading influence and geometrical large deformation. In this study, different kinds of material grading patterns and porosity distributions are used for the modelling of the FG structure. Initially, a mathematical model has been established by utilizing HSDT mid-plane kinematics along with Green Lagrange kind of nonlinear strain terms. The finite element technique is utilized for the discretization of the structure. And Hamilton's principle is adopted to obtain the governing equation of the FG structure and solved by utilizing a direct iterative method. Based on the mathematical model, a computer code in MATLAB is established for the calculation of the nonlinear frequencies. The suitability of the code has been checked by performing the validation and convergence tests. Lastly, the influence of several design parameters i.e., multi-directional grading, porosity distribution, grading patterns, amplitude ratio, curvature ratio, geometrical shapes, support conditions, thickness ratio and aspect ratio on the nonlinear eigenfrequency parameters is shown by presenting different numerical examples.

Automated summary

This study examines the eigenfrequency characteristics of the doubly-curved FG panel with multi-directional grading influence and geometrical large deformation. A mathematical model is established using HSDT mid-plane kinematics and Green Lagrange nonlinear strain terms, with finite element technique for discretization and Hamilton's principle for governing equation. A MATLAB computer code is developed for calculating nonlinear frequencies, validated and tested for convergence, showcasing the influence of various design parameters on nonlinear eigenfrequency parameters.