Fracture of brittle materials under uniaxial compression

Abstract

Fracture under compressive loading is distinctly different compared to fracture under tensile loading. One contributing factor is that interatomic bonds have to be stretched to be broken: compressing the interatomic spacing cannot break an interatomic bond. This is demonstrated by the fact that no fracture occurs in materials loaded in hydrostatic compression, even at extreme magnitudes. It is believed that fracture in compressive stress fields starts due to local tensile stresses which develop around a discontinuity (e.g. an air bubble). A 2D numerical study is conducted to study the effect of the shape and size of such a discontinuity on crack propagation in a macroscopic uniaxial compressive stress field. The results of this study highlight the major differences between tensile crack propagation and compressive crack propagation in brittle solids.