Lighter and Stronger,

Abstract

A new method has been developed that permits the direct design of shapes of two-dimensional structures ad structural components, loaded in their plane, within specified design constraints and exhibiting optimum distribution of stresses. The method uses photoelasticity and requires a large field diffused light polariscope. Several problems of optimization related to the presence of holes in finite and infinite plates, subjected to uniaxial and biaxial loadings, are solved parametrically. Some unexpected results have been found: (1) the optimum shape of a large hole in a bar of finite width, subjected to uniaxial load, is 'quasi' square, but the transverse boundary has the configuration of a 'hat'; (2) for the small hole in the large plate, a 'barrel' shape has a lower s.c.f. than the circular hole and appreciably higher coefficient of efficiency; (3) the optimum shape of a tube, subjected to diametral compression, has small 'hinges' and is much lighter and stronger than the circular tube. Applications are also shown to the design of dove-tails and slots in turbine blades and rotors, and to the design of star-shaped solid propellant grains for rockets. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1980
Accession Number
ADA081317

Entities

People

  • Augusto J. Durelli
  • K. Rajaiah

Organizations

  • Oakland University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Axial Loads
  • Boundaries
  • Coefficients
  • Compression
  • Geometry
  • Materials
  • Measurement
  • Polariscopes
  • Propellant Grains
  • Propellants
  • Solid Propellants
  • Stresses
  • Structural Components
  • Turbine Blades
  • Turbines
  • Two Dimensional
  • Waveplates

Fields of Study

  • Physics

Readers

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