Fracture Toughness Effects in Geomaterial Solid Particle Erosion

Effects of fracture toughness on the impingement of geomaterials (rocks and cementitious composites) by quartz particles at velocities between 40 and 140 m/s are investigated experimentally and analytically. If schist is excluded, relative erosion (in g/g) reduces according to a reverse power function if fracture toughness increases. The power exponent depends on impingement velocity, and it varies between −0.64 and −1.33. Lateral cracking erosion models, developed for brittle materials, deliver too high values for relative material erosion. This discrepancy is partly attributed to stress rate effects. Effects of R -curve behavior seem to be marginal. An integral approach E R = K 1 · E R P + (1 − K 1 ) · E R L is introduced, which considers erosion due to plastic deformation and lateral cracking. A transition function K 1 = f K Ic 12 / 4 / σ C 23 / 4 is suggested in order to classify geomaterials according to their response against solid particle impingement.