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International Journal for Multiscale Computational Engineering

ISSN for PRINT: 1543-1649

Institutional price:	$747.00
Issues per year:	6

Best Paper Award Selection - Editorial Board Site

2004, Volume2

170 pages

DOI: 10.1615/IntJMultCompEng.v2.i4

Issue price - $178.00

Analysis and Numerical Simulation of Discontinuous Displacements Modeling Fine Scale Damage in a Continuum Under Mixed-Mode Loading

Krishna Garikipati
University of Michigan, Ann Arbor, MI 48109

ABSTRACT

A continuum damage degradation model capable of representing mixed-mode failure is analyzed. The damage criteria are represented by multiple surfaces that bound the elastic domain in stress space. The compliance tensor is treated as an internal variable and evolves with damage. The damage evolution law is associative and of a nonhardening nature. A distributional framework is adopted for the kinematics. In order to model fine scale features, such as microcracks and microvoids, it is assumed that the solution admits discontinuous displacements. This implies singular distributional strain fields. Necessary conditions are arrived at for the existence of such solutions. It is demonstrated that an interpretation consistent with the presence of strongly discontinuous solutions is possible for this damage model. Furthermore, the analysis leads to a law that dictates the evolution of the solution in the postbifurcation regime. This is combined with an unloading modulus that degrades as damage progresses. Computations are performed in the framework of the Enhanced Strain Finite Element Method. The strain field is enhanced with functions capable of representing singular distributions. Several numerical examples that demonstrate independence of element size and mesh alignment are presented.