On brittle-ductile strain localization

The classification of the strain localization modes is attempted around brittle-ductile transition. The stresses are high. The are a number of suspects: earthquake-like thermal runaway (Braeck et al. 2009), stable sliding as shear heating zones oriented 45 degrees to the principal stresses (Kiss et al. 2019), brittle faults/shear bands oriented ca. 30 degrees to the maximum compressive principal stress and mode 1 fracture. The coupling to the porous fluid hydrology is accounted for.  High resolution numerical simulations are compared to classical and newly derived composite asymptotic solutions.

References

Braeck, S., Podladchikov, Y., & Medvedev, S., 2009. Spontaneous dissipation of elastic energy by self-localizing thermal runaway, Phys. Rev. E , 80, 046105, doi:10.1103/PhysRevE.80.046105.

Kiss, D., Podladchikov, Y., Duretz, T., & Schmalholz, S., 2019. Spontaneous generation of ductile

shear zones by thermal softening: Localization criterion, 1D to 3D modelling and application to the

lithosphere, Earth Planet. Sci. Lett., 519, 284–296, doi:10.1016/j.epsl.2019.05.026.