Effects of waviness on fiber-length distribution and interfacial shear strength of natural fibers reinforced composites

In order to account for fiber waviness, an effective fiber length is proposed in this paper. The undulation of the fibers is approximated with a sinusoidal arc along with a calculated new length. The proposed correction factor depends on the wavelength and amplitude of the wave approximating the fiber. To verify this method, blends of polylactic acid (PLA) and polycarbonate (PC) (prepared with and without an interchange reactions catalyst) with addition to various percentages of cellulosic fibers (5 wt%, 10 wt% and 15 wt%) have been prepared and characterized. It has been demonstrated that by considering the corrected length values, it is possible to predict the mechanical properties and the effective reinforcement attained in the composites by using the most widely used models. In particular, the prediction of the elastic modulus is slightly affected by this correction, whereas the calculation of IFSS is strongly dependent on it.