Dynamic damping modeling of composite with carbon nano fiber paper

Carbon nanomaterial reinforced polymer nanocomposites exhibit significant improvement in energy dissipation during dynamic loading, In addition to the intrinsic viscoelastic dissipation of the matrices and the fillers, the nano-scale interfaces play a critical role which has not been well quantified, especially in the high-frequency acoustic region. This paper reports on the efforts of quantifying the interfacial friction contribution to the damping in nanocomposites through mechanical modeling development. Upon mechanical loading, non-uniform stress in a carbon nanofiber reinforced composites (CNFC) increases with external force, which will cause gradual development of debonding at the interfaces. This interfacial debonding resulted friction force is a major source of the energy dissipation during dynamic loading. A micro-mechanical model was first used to quantify the debonding procedure of a single carbon nanofiber interface in one cell, and then the correspondence interfacial friction dissipation on the debonded partial of interface during a vibration periodic was modeled by integrating the angular and strain dependent interfacial normal stress, frequency dependent interfacial friction coefficient, and strain dependent interfacial mutual sliding length. The loss factor in the cell was then calculated through the analysis of the dissipated and stored energy. A comparison to the available experimental data was presented to justify the importance and characteristics of the dynamic interfacial friction in nanocomposited materials.