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Experimental Mechanics

, Volume 8, Issue 12, pp 539–547 | Cite as

A photoviscoelastic analysis of time-dependent stresses in a polyphase system

The technique of photoviscoelastic stress analysis is applied to an idealized model of a polyphase-material system having a viscoelastic binder in order to determine the time-dependent stress redistribution
  • R. M. Hackett
  • E. M. Krokosky
Article

Abstract

The method of photoviscoelastic stress analysis is used to predict time-dependent stress redistributions in a polyphase-material system having a viscoelastic binder and subjected to applied exteernal-loading conditions. The polyphase-material model studied is composed of a photoviscoelastic matrix material and contains rigid inclusions and voids, thus simulating a threephase composite system.

In order to perform the study, a photoviscoelastic model material is developed. An epoxy-resin system consisting primarily of Shell Epon 828 and Epon 871, optimized to display the properties desirable for such application, is utilized.

The time-dependent stess distributions obtained by the photoviscoelastic analysis are compared with results obtained by applying the “correspondence rule” to a finite-element solution for the elastic stress field of a mathematical model of the three-phase material system. The comparison of results indicates that the technique of photoviscoelastic stress analysis is extremely applicable to complex models such as the one studied. The feasibility of this application to more complex polyphase models with varying loading conditions is indicated.

Keywords

Mathematical Model Mechanical Engineer Fluid Dynamics Stress Field Complex Model 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

List of Symbols

aT

shift factor

Cf,Ci

parameters

Cσ,Cε

stress- and strain-optic coefficients

\(C_{\sigma r}- 1,C_{ \in c}- 1\)

relaxation birefringence-stress and creep birefringence-strain coefficients

E

material modulus

Fo,Fi

parameters

h

thickness

N,Nf,Ni

fringe orders

p

Laplace parameter

r, θ

polar coordinates

si

slope

T,To

temperatures

t

time

V1,V2

principal light-wave velocities

xi

orthogonal axes

αiii

parameters

1, ∈2

principal strains

ψ

directional angle

Φ

directional angle

ξ

ψ−Φ

θ

directional angle

ν

Poisson's ratio

σ1, σ2

principal stresses

τ

time variable

ρ, ρ, ρ0

densities

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Bibliography

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Copyright information

© Society for Experimental Mechanics, Inc. 1968

Authors and Affiliations

  • R. M. Hackett
    • 1
  • E. M. Krokosky
    • 2
  1. 1.Vanderbilt UniversityNashville
  2. 2.Carnegie-Mellon UniversityPittsburgh

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