Deformation characteristics of glass‐filled epoxy composite under compression: Role of filler shape and volume fraction

Abstract

Abstract The influence of filler shape on the compression behavior of low‐volume fraction glass‐filled epoxy composite is studied. Test materials are prepared by embedding two filler variants, spherical and slender, up to 10% volume fraction into the matrix. Although the slender fillers improve the yield and strain hardening characteristics of epoxy, the effect of spherical ones is observed only on the latter. The trends remain the same but magnifies when the filler content is increased. Optical analyses of deforming specimens reveal extensive presence of shear bands. The crushed sample micrographs show broken fillers and severe matrix cracking, indicating significant resistance to deformation provided by the slender fillers, whereas the debonded spherical particles appear to have lesser impact on the deformation characteristics. Finite strain elasto‐plastic finite element analyses on representative volume elements complement experimental observations. Simulations clearly indicate that the deformation in slender filler composites are filler dominated. On the contrary, due to large inter particle spacing, the matrix governs the deformation response in spherical particle composites. Interestingly, in any case, the inclusion shape has no effect on the average matrix stress.