Wave propagation responses of porous bi-directional functionally graded magneto-electro-elastic nanoshells via nonlocal strain gradient theory

This study examines the wave propagation characteristics for a bi-directional functional grading of barium titanate (BaTiO3) and cobalt ferrite (CoFe2O4) porous nanoshells, the porosity distribution of which is simulated by the honeycomb-shaped symmetrical and asymmetrical distribution functions. The nonlocal strain gradient theory (NSGT) and first-order shear deformation theory are used to determine the size effect and shear deformation, respectively. Nonlocal governing equations are derived for the nanoshells by Hamilton's principle. The resulting dimensionless differential equations are solved by means of an analytical solution of the combined exponential function after dimensionless treatment. Finally, extensive parametric surveys are conducted to investigate the influence of diverse parameters, such as dimensionless scale parameters, radius-to-thickness ratios, bi-directional functionally graded (FG) indices, porosity coefficients, and dimensionless electromagnetic potentials on the wave propagation characteristics. Based on the analysis results, the effect of the dimensionless scale parameters on the dispersion relationship is found to be related to the ratio of the scale parameters. The wave propagation characteristics of nanoshells in the presence of a magnetoelectric field depend on the bi-directional FG indices.

Automated summary

This study investigates the wave propagation characteristics of porous nanoshells made of barium titanate and cobalt ferrite, with simulated porosity distribution and the use of nonlocal strain gradient theory and first-order shear deformation theory. Various parameters, such as dimensionless scale parameters and bi-directional functionally graded indices, are examined to understand their influence on wave propagation characteristics. The findings suggest that the dispersion relationship is related to the ratio of scale parameters, and the wave propagation characteristics depend on the bi-directional functionally graded indices.