SCEC Award Number 11012 View PDF
Proposal Category Collaborative Proposal (Integration and Theory)
Proposal Title Dynamics of Branched Rupture, with Bimaterial and Elastic-Plastic Effects
Name Organization
Renata Dmowska Harvard University James R. Rice Harvard University
Other Participants DeDontney, Nora
SCEC Priorities A9, A7, A8 SCEC Groups FARM, GMP, CDM
Report Due Date 02/29/2012 Date Report Submitted N/A
Project Abstract
Factors governing rupture path selection at a branch junction are characterized by theoretical/numerical modeling, separately for the cases of elastic-plastic off-fault response and for rupture along a bi-material interface. Plasticity is shown to suppress local opening at the tip, as sometimes predicted in purely elastic analyses. For dissimilar media, side-branches are more likely to rupture when the branch is in a more compliant ("slower") material.
Intellectual Merit Rupture branching is important to the issues of whether a multi-segment rupture can develop. The main issues addressed are (or were when we started) untouched issues on rupture branching in the literature. Our work shows that some commonly adopted numerical schemes in rupture modeling are unable to deal properly with path selection at a branch when local opening occurs.
Broader Impacts The activity has been a major part of the Ph.D. research of Nora DeDontney.
Apart from the educational contribution, it does contribute to the problem of understanding how ruptures select their path through geometrically complex fault zones.
Exemplary Figure Fig. 2. Image of a branching junction some time after the rupture has propagated onto a compressive side branch and a small distance along the main fault. Contours show the shear
stress level. (a) Opening occurs at the junction for an elastic off-fault material. (b) Opening does not occur for an incohesive elastic-plastic material. (Also, it does not occur for materials with finite cohesion component, c, of strength up to a critical level of c/pre-stress.)