Porosity-dependent vibration and dynamic stability of compositionally gradient nanofilms using nonlocal strain gradient theory

Abstract

Porosity-dependent free vibration and dynamic stability of functionally graded nanofilms are studied according to the nonlocal strain gradient theory. Two-scale coefficients are considered to incorporate both nonlocality and strain gradient impacts. The nanofilm is subjected to in-plane hygro-thermal and harmonic mechanical loads. Uniform dispersion of porosities is considered according to a power-law model for functionally graded materials. Galerkin's approach is employed to obtain the vibration frequencies as well as stability regions. One can see that stability regions and vibration frequencies of a functionally graded nanofilm are significantly affected by static load parameter, dynamic load parameter, porosities, moisture change, temperature change, and elastic substrate nonlocal strain gradient coefficients.