Abstract

This paper describes the manufacturing of a family of epoxies, the Poisson's ratio of which at the critical temperature is on the order of 0.4. The variation of Young's modulus, Poisson's ratio, shear fringe value, and critical temperature as a function of the amount of hardener, the curing temperature, and the curing time for a large range of these variables are presented as parametric curves.

Previously, epoxies used in three-dimensional analysis have all shown a Poisson's ratio of about 0.5, indicating incompressibility. The new compressible material has two advantages: (1) it is closer to the common engineering materials and (2) strains can be measured at interior points to supplement photoelastic analysis, or strain measurements can be used exclusively to obtain stresses throughout the body.

Issue Section:
Research Papers
Keywords:
epoxy resins, stress analysis, photoelasticity, compressibility, Poisson ratio, strains, stress freezing

References

1.
Kuske
,
A.
, “
Das Kunsthans Phenolformaldehyd in der Spannungsoptik
,”
Forschung auf dem Gebiete des Ingenieurwesens
 0367-2204, Vol.
9
, No.
3
, May–June 1938, pp.
139
-
149
.
Crossref
Search ADS
 
2.
Frocht
,
M. M.
 and
Guernsey
,
R.
 Jr., “
A Special Investigation to Develop a General Method for Three-Dimensional Photoelastic Stress Analysis
,” NACA Report No. 1148,
National Advisory Committee for Aeronautics
, Washington, D.C.,
1952
.
3.
Hetenyi
,
M.
,
Handbook of Experimental Stress Analysis
,
Wiley
,
New York
,
1950
, pp.
767
-
770
.
4.
Frocht
,
M. M.
,
Photoelasticity
,
Leven
 
M. M.
, Ed.,
Pergamon Press
,
New York
,
1969
, pp.
13
-
14
.
5.
Heywood
,
R. B.
,
Photoelasticity for Designers
,
Pergamon Press
,
New York
,
1969
.
6.
Durelli
,
A. J.
 and
Riley
,
W. F.
,
Introduction to Photomechanics
,
Prentice-Hall
,
Englewood Cliffs, N.J.
,
1965
.
7.
Frocht
,
M. M.
,
Photoelasticity
, Vol.
2
,
Wiley
,
New York
,
1948
.
8.
Durelli
,
A. J.
,
Hasseem
,
H. M.
, and
Parks
,
V. J.
, “
New Experimental Methods in Three-Dimensional Elastostatics
,” ONR Report No. 33,
Office of Naval Research
, Washington, D.C.,
12
1973
.
9.
Leven
,
M. M.
, “
Epoxy Resins for Photoelastic Use
” in
Proceedings of Symposium on Photoelasticity
,
Pergamon Press
,
New York
,
10
1961
, pp.
145
-
165
.
Google Scholar
Crossref
Search ADS
 
10.
Parks
,
V. J.
,
Durelli
,
A. J.
,
Chandrashekhara
,
K.
, and
Chen
,
T. L.
, “
Stress Distribution Around a Circular Bar, with Flat and Spherical Ends Embedded in a Triaxial Stress Field
,”
Journal of Applied Mechanics, Series E, Transactions
, American Society of Mechanical Engineers, Vol.
37
, No.
3
,
09
1970
, pp.
578
-
586
.
Google Scholar
Crossref
Search ADS
 
11.
Lee
,
Henry
 and
Neville
,
Kris
,
Epoxy Resins
,
McGraw-Hill
,
New York
,
1957
.
12.
Durelli
,
A. J.
, “
Complete Experimental Solution of Three Dimensional Elastic Problems
,”
Journal of Strain Analysis
 0022-4758, Vol.
10
, No.
2
,
01
1975
, pp.
42
-
52
.
13.
Durelli
,
A. J.
 and
Ferrer
,
L.
, “
New Methods to Determine Elastic Constants
,”
Materials Research and Standards
 0025-5394, MTRSA, Vol.
3
, No.
12
,
12
1963
, pp.
988
-
991
.
14.
Sampson
,
R. C.
, “
A Three-Dimensional Photoelastic Method for Analysis of Differential-Contraction Stresses
,”
Experimental Mechanics
, Vol.
3
, No.
10
,
10
1963
, pp.
225
-
235
.
Google Scholar
Crossref
Search ADS
 
15.
Hendry
,
A. W.
,
Photoelastic Analysis
,
Pergamon Press
,
New York
,
1966
.
This content is only available via PDF.
All rights reserved. This material may not be reproduced or copied, in whole or in part, in any printed, mechanical, electronic, film, or other distribution and storage media, without the written consent of ASTM International.
You do not currently have access to this content.