EXPERIMENTAL STUDY ON THE STRUCTURAL DAMPING OF FIBER-FILLED HOLLOW PROFILES

Since mass, stiffness and damping are coupled design variables of fiber-reinforced plastics in terms of their dynamic behavior, a lightweight design often results in vibration-prone components. A novel approach to increase damping while maintaining or even increasing stiffness is proposed in this experimental study. The idea is to introduce tightly packed dry carbon fibers into small cavities to dissipate vibration induced energy. This experimental study presents the manufacturing process of specially designed specimens to investigate the proposed damping measure as well as their dynamical characterization by a bending resonance test. The focus was to identify the influence of the tightly packed carbon fibers on the dynamical bending stiffness and the structural damping. Therefore, three types of beam-shaped specimens were manufactured; with through-holes (type A), made of solid material (type B) and with carbon fibers inside the through-holes (type C). The loss factor of the specimens of interest (type C) increased approx. by a factor of 3 in comparison to the reference specimens type A and B. In addition to this significant increase in damping, an increase of the eigenfrequency was measured.