Is it possible to generate a spontaneous rupture by loading the crust through the boundary conditions without prescribing a time step between ruptures?
I am thinking of something similar to step6 in 2d subduction but without determining the timing of ruptures. Meaning, the rupture would nucleate when the fault is loaded to the yield stress by the boundary conditions, not at a fixed time interval. I am not interested in simulating several earthquake cycles, just in nucleating one or two ruptures to see how different loading conditions affect the nucleation time. I should also note I am using slip weakening friction, not a rate and state ageing law.
Yes, it is possible. See
examples/2d/subduction/step05 in v2.2.2 (also in v2.2.1).
Thank you. Is it possible to do it without having initial tractions on the fault? I am trying to troubleshoot whether the traction error I have posted about in the forum before is related to something other than the solver tolerances because the issue persists despite using the recommended tolerances.
You can do it without applying initial tractions on the fault. In most cases it makes sense to use at least a simple background stress model for the initial tractions; otherwise, it takes a very long time to load the fault and you may end up with a stress state that is inconsistent with the geologic history.