1. Theoretical Model: Slip propagation
Slip on frictional discontinuities starts on weak areas
and propagates towards strong areas.
The critical energy release rate GIIC, which is a
predictor for slip initiation, is not a material property.
GIIC increases with confinement for those
discontinuities with different peak and residual shear
strengths.
GIICcan be used as predictor for initiation of shear
(frictional) cracks.
Crack Tip
Back Lobe
Front Lobe
Weak Area
Strong Area
Slip propagation
theoretical
model
detail v
Pre-existing fracture
coalescence through
shear crack
Pre-existing
fracture
Schematic
Increased
surface
roughness
Theoretical Model: