Optimization of Geometric Discontinuities in Stress Fields.

Abstract

The ideal boundary of a discontinuity is defined as that boundary along which there is no stress concentration. Photoelastically an isochromatic coincides with the ideal boundary. This property is used to develop experimentally ideal boundaries for some cases of technological interest. The concept of 'coefficient of efficiency' is introduced to evaluate the degree of optimization. The procedure to idealize boundaries is illustrated for the two cases of the circular tube and of the perforated rectangular plate, with prescribed functional restraints and a particular criterion for failure. An ideal design of the inside boundary of the tube is developed with decreases its maximum stress by 25%, at the time it also decreases its weight by 10%. The efficiency coefficient is increased from 0.59 to 0.95. Tests with a brittle material show an increase in strength of 20%. An ideal design of the boundary of the hole in the plate reduces the maximum stresses by 26% and increases the coefficient of efficiency from 0.54 to 0.90. (Author)

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1978
Accession Number
ADA051453

Entities

People

  • Augusto J. Durelli
  • Kenneth Brown
  • P. Yee

Organizations

  • Oakland University

Tags

Communities of Interest

  • Ground and Sea Platforms
  • Space
  • Weapons Technologies

DTIC Thesaurus Topics

  • Air Force
  • Civil Engineering
  • Composite Materials
  • Engineering
  • Engineers
  • Geometry
  • Materials
  • Measurement
  • Mechanical Engineering
  • Mechanics
  • Military Research
  • New York
  • Physics Laboratories
  • Propellant Grains
  • Solid Propellants
  • Three Dimensional
  • Two Dimensional

Readers

  • Combustion and Flow Dynamics.
  • Mechanical Engineering/Mechanics of Materials.
  • Structural Dynamics.