# gst: pulse-to-crack transition, unsteady slip pulses under spatially-varying prestress scenarios.

AA << study the effects of a spatially-varying prestress τb(x) on 2D slip pulses, initially generated under a uniform τb along a rate-and-state friction fault. (They) consider periodic and constant-gradient prestress τb(x) around the reference uniform τb. For a periodic τb(x), pulses either sustain and form quasi-limit cycles in the L−c plane or decay predominantly monotonically along the L(c) line, depending on the instability index of the initial pulse and the properties of the periodic τb(x).  >>️

<< For a constant-gradient τb(x), expanding/decaying pulses closely follow the L(c) line, with systematic shifts determined by the sign and magnitude of the gradient. (They) also find that a spatially-varying τb(x) can revert the expanding/decaying nature of the initial reference pulse.  >>

<< Finally, (AA) show that a constant-gradient τb(x), of sufficient magnitude and specific sign, can lead to the nucleation of a back-propagating rupture at the healing tail of the initial pulse, generating a bilateral crack-like rupture. This pulse-to-crack transition, along with the above-described effects, demonstrate that rich rupture dynamics merge from a simple, nonuniform prestress. >>️️

Anna Pomyalov, Eran Bouchbinder. Unsteady slip pulses under spatially-varying prestress. arXiv: 2407.21539v1 [cond-mat.mtrl-sci]. Jul 31, 2024.

https://arxiv.org/abs/2407.21539

Also: transition, instability, crack, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, transition, instability, crack