University of Illinois Urbana-Champaign

Correlation of variables in photoelastic stress freezing

Cook, R.D.

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https://hdl.handle.net/2142/111871

Description

Title
Correlation of variables in photoelastic stress freezing
Author(s)
Cook, R.D.
Issue Date
1960-05
Keyword(s)
Photoelastic Stress Freezing
Date of Ingest
2021-11-04T16:22:32Z
Abstract
The experimental work shows how the material (Araldite 6020 epoxy resin cured with phthalic anhydride) deforms and behaves photoelastically at various temperatures. Quantitative relationships between strain, fringe order, stress, time and temperature are determined experimentally. These relationships are explained upon the theory that the material contains two types of bonds in its molecular structure, one of these types being van der Waal bonds which become ineffective at high temperature, the other type being covalent bonds which retain their effectiveness at both high and low temperatures. The temperature of maximum optical sensitivity is found, and the temperature below which the properties of the material are not time dependent is determined. It is shown that above the temperature of maximum optical sensitivity, Young’s modulus increases and the optical sensitivity decreases with increasing temperature, while the figure of merit remains constant. It is shown that the distribution of fringes in a photoelastic model will change if the model is loaded at a temperature at which the properties of the material are time dependent, and evidence is presented which indicates that the stress freezing technique cannot help but be in error by a small amount.
Publisher
Department of Theoretical and Applied Mechanics. College of Engineering. University of Illinois at Urbana-Champaign
Series/Report Name or Number
  • TAM R 162
  • 1967-0458
ISSN
0073-5264
Type of Resource
text
Language
eng
Permalink
http://hdl.handle.net/2142/111871
Copyright and License Information
Copyright 1960 Board of Trustees of the University of Illinois

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Technical Reports - Theoretical and Applied Mechanics (TAM) PRIMARY
TAM technical reports include manuscripts intended for publication, theses judged to have general interest, notes prepared for short courses, symposia compiled from outstanding undergraduate projects, and reports prepared for research-sponsoring agencies.