Eigenfrequency Analysis Method of FRP Structures

摘要

Fiber reinforced plastics(FRP) have been extensively used as structural materials in light- weight structures such as spacecraft application, because of its high-stiffness and low-density properties. Recent composite structures have been involved in more complicated design. In most of the structures using these materials, separate parts or frames are often assembled using adhesively-bonded joints, which replaced bolts and rivets. These joints generally reduce the vibration damping of structures as well as strength properties. It is thus very important to improve dynamic properties such as vibration damping property, fatigue resistance and impact property of FRP structures. This work investigates the vibration damping properties of FRP laminates and FRP adhesively-bonded joints from both the analytical and experimental viewpoints. It is well known that it is difficult to predict the mode shape of vibration for complicated FRP structures. In this prediction, the finite element method will be powerful and convenient tool. The conventional solid model is sometimes applied to an eigenvibration problem of the adhered plane structure, because the eigenvibration mode is a complicated three-dimensional deformation. However, the application of the solid elements requires a long solution time. The main reason is due to the large aspect ratio of the plane structure.