Concrete, ceramic, and other quasi-brittle materials contain pre-existing cracks and complex structure on various internal length-scales. Quantifying the fracture behavior of these heterogeneous materials using different testing methods is a challenge and is an argumentative subject [1]. To selectively study…
Concrete, ceramic, and other quasi-brittle materials contain pre-existing cracks and complex structure on various internal length-scales. Quantifying the fracture behavior of these heterogeneous materials using different testing methods is a challenge and is an argumentative subject [1]. To selectively study the impact of microstructure on micro-scale fracture parameter this article presents an experimental and theoretical investigation of the fracture toughness of a representative composite material consisting of glass beads embedded in epoxy using microscratching and conventional three-point bending tests. Existing analysis formulas for microscratch data assumes homogeneity near the indenter tip. This study finds that this assumption may need to be reconsidered. By controlling the volume fraction of glass beads (representing an inclusion) in the matrix of the composite material, it is possible to control the amount, or direction, of crack development and reduce the stress concentration within the material during loading [1]. As a result, an increase in the fracture toughness of the composites and improved fracture properties is obtained.