Surface Fractal Analysis for Estimating the Fracture Energy Absorption of Nanoparticle Reinforced Composites

Brahmananda Pramanik; Tezeswi Tadepalli; P Raju Mantena

doi:10.3390/ma5050922

Surface Fractal Analysis for Estimating the Fracture Energy Absorption of Nanoparticle Reinforced Composites

Materials (Basel). 2012 May 23;5(5):922-936. doi: 10.3390/ma5050922.

Authors

Brahmananda Pramanik¹, Tezeswi Tadepalli², P Raju Mantena³

Affiliations

¹ Department of Mechanical Engineering, University of Mississippi, University, MS 38677, USA. bpramani@olemiss.edu.
² Department of Mechanical Engineering, University of Mississippi, University, MS 38677, USA. tadepali@olemiss.edu.
³ Department of Mechanical Engineering, University of Mississippi, University, MS 38677, USA. meprm@olemiss.edu.

Abstract

In this study, the fractal dimensions of failure surfaces of vinyl ester based nanocomposites are estimated using two classical methods, Vertical Section Method (VSM) and Slit Island Method (SIM), based on the processing of 3D digital microscopic images. Self-affine fractal geometry has been observed in the experimentally obtained failure surfaces of graphite platelet reinforced nanocomposites subjected to quasi-static uniaxial tensile and low velocity punch-shear loading. Fracture energy and fracture toughness are estimated analytically from the surface fractal dimensionality. Sensitivity studies show an exponential dependency of fracture energy and fracture toughness on the fractal dimensionality. Contribution of fracture energy to the total energy absorption of these nanoparticle reinforced composites is demonstrated. For the graphite platelet reinforced nanocomposites investigated, surface fractal analysis has depicted the probable ductile or brittle fracture propagation mechanism, depending upon the rate of loading.

Keywords: digital microscopy; fractal dimension; fracture energy; fracture toughness; fractured surface; low velocity punch-shear; nanocomposites.