| | AbstractWe propose a new
boundary integral equation method (BIEM) to model the spontaneous
propagation of rupture on a planar fault embedded in a homogeneous
elastic medium. The BIEM formulation is very compact and fast in
computation, so that we are able to study the effect of different slip-
and rate-dependent friction laws on dynamic shear fault propagation. We
simulated a spontaneous rupture by a sudden break of asperity under two
friction laws, rate and/or slip weakening. We examined both long and
circular asperities. The long asperity model corresponds to the 2D
anti-plane or in-plane problem. The obtained result shows that
slip-weakening friction is important at the crack tip, and
rate-weakening friction plays an important role in the healing stage. If
slip-weakening friction is strong stress drops gradually at the crack
tip. On the other hand, if rate-weakening friction is strong stress
drops abruptly, but it stops suddenly and sometimes stress recovers.
This sudden stop of rupture produces a heterogeneous stress
distribution, which will in turn produce aftershocks. Finally, we
studied a realistic asperity model in which rupture starts from a small
patch and then propagates with finite rupture speed. Depending on the
asperity size healing can occur even without rate-weakening friction.
This is due to very strong healing waves produced by the edges of the
asperity.Return to Table of
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