The aim of this study was to research the effect of carbon nanofiber (CNF), the microballoon (MB) volume fraction and its density on both the vibration properties and impact behavior of carbon nanofiber – reinforced syntactic foam. Twelve different types of syntactic foam were produced with two different CNF contents, two different MB densities and two different MB volume fractions. Neat epoxy, syntactic foams with and without carbon nanofiber were manufactured for characterization by comparing each other in terms of mechanical and dynamic properties. With the free vibration tests, natural frequencies and damping ratios were investigated. Besides vibrations tests, low-velocity impact and tensile tests were conducted on the syntactic foams. Analyses of the results were performed on the effect of the volume fraction of additives and MB density on the vibration, impact and tensile behavior of the syntactic foams. In addition, SEM was used to understand the microstructure of the samples tested. Vibration results presented that the presence of carbon nanofiber enhanced strength but was not effective on damping, while low-velocity impact, and tensile test results also demonstrated the same trend.
Read full abstract