Multiscale Computations of Microcracking Solids

Abstract

New multiscale methods have been developed for the study of microcracking and dislocations. The multiscale method for microcracking aggregates the effect of an arbitrary number of cracks at the micro level into a single equivalent crack at the macrolevel. The methodology is based on the concept of a perforated unit cell, which excludes all subdomains of the unit cell where the material loses stability in the averaging operations. We have shown that for this approach, the macro bulk material does not lose ellipticity when failure occurs. This is an important development since it avoids the ill-posedness usually associated with multiscale modeling of failure. Comparisons with direct numerical simulations show excellent accuracy. We have also developed new models for dislocations and concurrent methods that couple atomistic models with these new continuum dislocation methods. These enable dislocation dynamics in arbitrary geometries and materials to be modeled in terms of fundamental physics.

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Document Details

Document Type
Technical Report
Publication Date
Jul 08, 2009
Accession Number
ADA510248

Entities

People

  • Ted Belytschko

Organizations

  • Northwestern University

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms

DTIC Thesaurus Topics

  • Composite Materials
  • Computations
  • Coordinate Systems
  • Cracks
  • Discontinuities
  • Dislocations
  • Elements
  • Fibers
  • Finite Element Analysis
  • Geometry
  • Material Degradation Processes
  • Materials
  • Mechanics
  • Models
  • Molecular Dynamics
  • Multiscale Models
  • Quantum Dots

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