The
dynamics of the onset of frictional slip
Authors:
The Racah Institute of Physics, The
The way in which a frictional interface fails
is critical to our fundamental understanding failure processes in fields ranging
from engineering to the study of earthquakes. Frictional motion is initiated by
rupture fronts that propagate within the thin interface that separates two
sheared bodies. By measuring the shear and normal stresses along the interface together
with the subsequent rapid real contact area dynamics, we find that the ratio of
shear stress to normal stress can locally far exceed the static friction
coefficient without precipitating slip. Moreover, different modes of rupture selected
by the system correspond to distinct regimes of the local stress ratio. These
results indicate the key role of nonuniformity to frictional
stability and dynamics with implications for the prediction, selection and
arrest of different modes of earthquakes.