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Can flash heating of asperity contacts prevent melting?
Author(s) -
Bizzarri A.
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2009gl037335
Subject(s) - slipping , asperity (geotechnical engineering) , flash (photography) , instability , homogeneous , mechanics , shear (geology) , materials science , traction (geology) , fault (geology) , geology , composite material , optics , thermodynamics , geometry , physics , seismology , mathematics , geomorphology
We solve the elasto‐dynamic problem for a 3‐D rupture, spontaneously propagating on a fault, obeying rate‐ and state‐dependent friction. We explore, through numerical simulations with physically realistic constitutive parameters, the effects on dynamic traction evolution of the flash heating of microscopic asperity contacts. Our results demonstrate that the inclusion of flash heating tends to increase the degree of instability of a homogeneous fault: the supershear rupture regime is favored, significantly larger stress drops are realized and weakening distance and fracture energy increase. We show that the key parameter which controls the temperature evolution and the activation of the flash heating is the slipping zone width, 2 w . We found that for localized shear the rupture exhibits a pulse‐like behavior. On the contrary, for large slipping zones, the rupture develops as a sustained crack. Finally, we show that flash heating enhances the onset of melting.