Numerical Free Vibration Analysis of Sandwich Beams with a Steel-Ceramic FGM Core and FG-CNTRC Facesheets

The sandwich beams composed of a functionally graded material (FGM) core and functionally graded carbon nanotube-reinforced composite (FG-CNTRC) facesheets have been rarely studied. In this context, this study intends to profoundly investigate their free vibration characteristics, by introducing an effective and reliable FE analysis model. The FGM core is made of a steel-ceramic material, while the FG-CNTRC facesheets are manufactured with polymer and carbon nanotubes (CNTs). The effective material properties of the FGM core and FG-CNTRC facesheets are estimated using the linear rule of mixture. A FE analysis model is generated by dividing the beam into a finite number of homogenized sub-layers, and its reliability is secured by comparing its results with the reference solutions. The parametric study is conducted to profoundly investigate the effects of various parameters, such as the volume fraction of base materials, CNT distribution, core-to-face-sheet-thickness ratio, length-to-thickness ratio, and the boundary condition. The numerical results are discussed, and the main conclusions are explained.