Free vibration behaviour and some mechanical properties of micro particle reinforced epoxy composites

Abstract The epoxy composite specimens of certain sizes were produced by adding graphite, silicon carbide and boron carbide microparticles separately at the rates of 5, 10 and 15 wt% to the epoxy resin. Free vibrations of these composite samples were investigated experimentally in a simple supported vibration test setup. Frequency spectrums were obtained by modal analysis method in this experimental setup. The damping ratios were calculated using the half power bandwidth method. The mechanical properties of these composite specimens were also determined by applying the tensile test. By controlling the obtained vibration values theoretically, the effects of microparticle contributions to these specimens at certain rates on natural frequency and damping properties were investigated in detail. The maximum reduction in natural frequency was observed at 5 wt% of each reinforcement. Only the first natural frequency of the 15 wt% boron carbide reinforced epoxy composite was slightly increased. The damping ratio was increased at 10 wt% graphite added and 5 wt% boron carbide added epoxy composites compared to pure epoxy, but decreased in other composite specimens.