HR: 1340h
AN: T33C-1486    [Abstracts]
TI: Modeling Propagating Discontinuities in Finite Elements with Linear Displacement Jumps
AU: * Foster, C D
EM: fosterc@uic.edu
AF: University of Illinois at Chicago, Department of Civil and Materials Engineering (MC 246) College of Engineering 3085 Engineering Research Facility 842 West Taylor St., Chicago, IL 60607, United States
AB: Finite elements with embedded discontinuities have been developed over the course of a more than a decade. Upon detection of a failure condition, a surface can be added in these elements at an orientation consistent with the critical angle of the failure condition, and at a location consistent with the propagating fracture. Displacements may then occur along this surface according to a post-localization constitutive law. Hence, the element may be used to track propagating deformation bands and fractures through a body. Until recently, however, the embedded displacement jump in the element was limited in that it had to be constant in that element, disallowing a jump in the strain and stress fields on opposite sides of the discontinuity. In many fault systems, however, there is relative tension on one side of the fault in the direction parallel to the fault. This is especially true at the ends of the fault, where the behavior can significantly affect the propagation, and lead to secondary cracking and other structures. We enhance the kinematics of the element to account for linear displacement jumps, thus allowing for stress and strain jump across the element, while maintaining traction continuity. This enhancement allows for more realistic capturing of the stresses along a fault, and hence more realistic propagation. It is also a preliminary step in modeling secondary cracking (e.g. splay cracks) in the system. We apply this element to some example problems from the literature.
DE: 3225 Numerical approximations and analysis (4260)
DE: 5104 Fracture and flow
DE: 8010 Fractures and faults
DE: 8012 High strain deformation zones
DE: 8118 Dynamics and mechanics of faulting (8004)
SC: Tectonophysics [T]
MN: 2007 Fall Meeting