The Overall Response of Composite Materials Undergoing Large Deformations

Abstract

This research deals with the theoretical prediction of the effective behavior of nonlinear composite materials undergoing large deformations. In particular, applications are envisaged to the high temperature creeping behavior of metal/metal, metal/ceramic composites, and also of porous materials. Both isotropic and anisotropic configurations are considered including the technologically important case of fiber-reinforced composites, and the fundamentally important case of polycrystalline aggregates. The approach is based on new variational principles developed recently by the author (under AFOSR sponsorship), which allow the estimation of the overall behavior of a given nonlinear composite in terms of the effective properties of a suitably optimized linear comparison composite (with the same microstructure). The key advantage of the method is that it allows direct application of the extensive literature on linear composite materials, in the form of estimates and rigorous bounds, to obtain corresponding results for nonlinear composites. Additionally, the procedure is remarkably simple to implement, and the final results are usually expressed in terms of finite-optimization problems, which can be readily solved with modest computational effort. Recent progress include the application of the method to the determination of extremal yield surfaces for anisotropic rigid/plastic systems, and to the computation of estimates for the effective yield stress of polycrystalline aggregates.

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Document Details

Document Type
Technical Report
Publication Date
Oct 15, 1992
Accession Number
ADA259278

Entities

People

  • Pedro Ponte CastaƱeda

Organizations

  • University of Pennsylvania

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Ceramic Matrix Composites
  • Command And Control
  • Composite Materials
  • Crystal Structure
  • Elastic Properties
  • Fiber Reinforced Composites
  • Laminates
  • Materials
  • Materials Science
  • Mechanical Properties
  • Mechanics
  • Metal Matrix Composites
  • Micromechanics
  • Stress Strain Relations
  • Two Dimensional
  • Variational Principles
  • Yield Strength

Readers

  • Operations Research
  • Reinforced Composite Materials
  • Structural Dynamics.