Influence of Lamination of Composite Materials on the Vibration Characteristics of Laminated Circular Cylindrical Shells

The use of Filament-Wound (FW) formed structures with fiberreinforced composite materials has increased steadily during the past three decades in weight-sensitive structure, such as aerospace vehicles and automotive applications. Since FW formed structures have different elastic properties depending upon the fibre-direction, they show various dynamic characteristics due to weaken transverse stiffnesses. In this paper, the natural frequencies of FW graphite/epoxy pipes (cylindrical shells) for simply supported at both ends are evaluated account for transverse shear deformation and transverse normal strain based on the First-order Shear Deformation Theory (FSDT). The purpose of this study is to investigate the vibration behavior of composite pipes for the convenience of dynamic design. It is shown that natural frequencies of laminated composite cylindrical shells are strongly dependent on not only shell geometry and anisotropy properties of composite materials but also stack of a number of laminates. Consequently, using knowledge in this study the structural designer can tailor the strength and other properties of a composites to meet the requirements of a given application by virtue of these knowledge of the lamination technique.