Effect of fiber array on damping behaviors of fiber composites

This study aims to investigate the fiber array effect on modal damping behaviors of fiber composites. Three different fiber arrays, i.e., square edge packing (SEP), square diagonal packing (SDP), and hexagonal packing (HP), were considered to represent the microstructures of the unidirectional composites. Repeating unit cells (RUCs) suitable for describing the characteristics of the microstructure were adopted in the generalized method of cell (GMC) micromechanical analysis. The energy dissipation concept was then employed to calculate the specific damping capacities of composites in the material principal directions. The specific damping capacities obtained from micromechanical analysis were regarded as the equivalent damping properties homogenizing in the composites. In conjunction with the modal shapes of the composite structures determined from the finite element analysis, the specific damping capacity was extended to characterize the corresponding modal damping of the composite rods and plates. Both free–free and clamped-free boundary conditions were taken into account in the composite structures. Results indicated that the structures constructed from the composites with SDP fibers exhibit better damping behaviors than the other two cases.