Abstract
Size effect of particle on mode I fracture energy of epoxy composites filled with spherical silica particles was investigated experimentally. The spherical silica particles with various particle diameters ranging from 1.56μm to 240 nm and various volume fractions from 0 to 0.15 were added to the epoxy resin as matrix material to manufacture specimens. The fracture toughness G_<IC> was confirmed to depend greatly on the particle size. Areas of uneven fracture surfaces for the specimens were measured by a scanning electron microscope. Surface energies of the specimens were evaluated by using the fracture surfaces. The surface energy was found to be governed only by particle size.
