Filler shape and volume fraction effect on dynamic compression behaviour of glass filler reinforced epoxy composites

Abstract

The effect of filler shape and volume fraction on the dynamic compression behaviour of low volume fraction rigid particle filled polymer composites is demonstrated by performing experiments using split-Hopkinson pressure bar (SHPB) setup. The results indicate negligible influence of spherical particles on the mechanical behaviour of composites due to the large inter-particle separation distance at low volume fractions. On the contrary, the mechanical behaviour of composites is considerably affected by milled-fibres due to the large surface area to volume ratio of slender fillers which significantly decreases the inter-particle separation distance. The computational analysis in combination with experimental observations reveals two competing deformation mechanisms, the constraints provided by fillers to the polymeric chain movements and increasing strain softening in the matrix due to magnified stresses in between the particles. Depending upon the filler volume fraction one of the two mechanisms dominates, thus tailoring post-yield stress vs. strain curves of filled polymers.

Mechanical Behavior Modelling and Filler Geometry Effect of Glass Filler Reinforced Starch-Epoxy Hybrid Matrix Composites

“…As stated by Yesgat et al [ 22 ], most studies on mechanical characterization, and in particular on the fracture mechanics of particulate composites, are conducted either by reinforcing with regular shaped (mostly spherical) particles or by embedding randomly shaped fillers into the matrix material [ 23 , 24 , 25 ]. However, there are far fewer studies on the effect of the filler geometry of the same material on the mechanical properties of a polymer composite [ 26 , 27 , 28 , 29 , 30 ]. The results on the mechanical behavior of composite materials filled with different geometries/shapes of the same material in the scientific community are few and sometimes contradictory.…”

“…Kushvaha et al [ 27 ] concluded that the rod-shaped fillers produce the highest crack initiation toughness as well post-initiation KI values followed by flakes and spheres, respectively, while Malucelli et al [ 29 ] did not discover a discernable difference in the dynamic properties of his ZnO filled composites with respect to filler geometry. Singh et al [ 26 ] reported that spherical particles had a negligible influence on the stress vs. strain curves of composites, attributed to the large inter-particle separation distance, while the mechanical behavior of composites is considerably affected by milled-fibers due to the relatively larger surface area to volume ratio of fillers.…”