Dynamic Analysis of Functionally Graded Carbon Nanotube-Reinforced Composite Viscoelastic Shells

PurposeIn this study, functionally graded carbon nanotube reinforced composite viscoelastic shells' dynamic behaviour is investigated. The use of carbon nanotubes enhances material properties such as strength, stiffness, and thermal resistance, enabling tailored performance. By leveraging metals' high strength and ceramics' thermal and corrosion resistance, functionally graded materials eliminate interface issues through continuous property variation. Traditional forced vibration analysis often neglects internal damping impacts, leadings to inaccuracies in mechanical response prediction. To overcome this limitation, Kelvin viscoelastic model is employed.MethodsThe strain and stress distribution shape function is employed to determine the displacement field, while a higher-order shear deformation theory is employed for these shape functions. The motion 's equations are obtained via Hamilton's principle in Laplace domain. Furthermore, viscoelasticity of the material is taken into account by employing Kelvin's viscoelastic model for the solid bodies. The displacements calculated in Laplace domain are converted to time domain by using Durbin's modified inverse Laplace transform technique.ResultsThe developed method's validity is verified through free vibration analysis. Additionally, a comprehensive parametric study is carried out, encompassing both free and forced vibration analyses. The study investigates the impacts of various geometric properties, carbon nanotube distributions, material gradation, and viscoelastic material characteristics on fundamental frequencies and displacements.ConclusionThis study provides insights into the dynamic behaviour of functionally graded carbon nanotube reinforced composite viscoelastic shells.