Effective mechanical properties of ‘‘fuzzy fiber’’ composites

In this paperwe investigate themechanical behavior of carbonfiber composites,where the carbonfibers are coated with radially aligned carbon nanotubes. For this purpose we develop a general micromechanics method for fiber composites, where fibers are coated with radially aligned microfibers (‘‘fuzzy fiber’’ composites). The mechanical effective properties are computed with a special extension of the composite cylindersmethod. The in-plane shearmodulus is determinedusing anextendedversion of theChristensen’s generalized self consistent composite cylinders method. The proposed methodology provides stress and strain concentration tensors. The results of the method are compared with numerical approaches based on the asymptotic expansion homogenization method. The combination of composite cylinders method and Mori–Tanaka method allows us to compute effective properties of composites with multiple types of ‘‘fuzzy fibers’’. Numerical examples of compositesmade of epoxy resin, carbonfibers and carbon nanotubes are presented and the impact of the carbon nanotubes length and volume fraction in the overall composite properties is studied. 2012 Published by Elsevier Ltd.