Optimization of Composite Structures Subject to Local Stress Constraints

Abstract

An extension of current methodologies is introduced for optimization of graded microstructure subject to local stress criteria. The method is based on new multiscale stress criteria given by macrostress modulation functions. The modulation functions quantify the intensity of local stress fluctuations at the scale of the microstructure due to the imposed macroscopic stress. The methodology is illustrated for long cylindrical shafts reinforced with stiff cylindrical elastic fibers with generators parallel to the shaft. Examples are presented for shaft cross sections that possess reentrant corners typically seen in lap joints and junctions of struts. It is shown that the computational methodology delivers graded fibers microgeometries that provide overall structural rigidity while at the same time tempering the influence of stress concentrations near reentrant corners.

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Document Details

Document Type
Technical Report
Publication Date
May 01, 2005
Accession Number
ADA517920

Entities

People

  • Michael Stuebner
  • Robert Lipton

Organizations

  • University of Minnesota

Tags

Communities of Interest

  • Air Platforms
  • Space

DTIC Thesaurus Topics

  • Air Force
  • Algorithms
  • Applied Mathematics
  • Boundaries
  • Composite Materials
  • Composite Structures
  • Equations
  • Geometry
  • Gray Scale
  • Identification
  • Materials
  • Mathematics
  • Microstructure
  • Optimization
  • Stress Concentration
  • Topology
  • Topology Optimization

Readers

  • Computational Fluid Dynamics (CFD)
  • Materials Science and Engineering.
  • Mechanical Engineering/Mechanics of Materials.