Hygro-thermal vibration analysis of pre-/post-buckled FG-CNTRC nanobeams using nonlocal elasticity theory

This study presents an analytical investigation of the free vibration behavior of functionally graded carbon nanotube-reinforced composite nanobeams under hygro-thermal environments. The reinforcement of carbon nanotubes within the isotropic polymer matrix is considered in four distribution patterns: one uniform and three functionally graded distribution types. The material properties of both the carbon nanotubes and the matrix are assumed to be temperature-dependent, and the effective properties are estimated using the extended rule of mixtures. The governing equations are formulated based on the refined shear deformation beam theory in conjunction with nonlocal elasticity theory and are analytically solved for simply supported boundary conditions. The analytical results are first validated against available literature, and then extensive parametric studies are conducted to explore the effects of geometric dimensions, temperature and moisture levels, the nonlocal parameter, and various beam theories on the vibrational behavior of nanobeams.