Experimental Mechanics

, Volume 24, Issue 2, pp 150–156 | Cite as

Photoviscoelastic analysis of thermal stress in a quenched epoxy beam

The transient-thermal stress and strain in an epoxy beam subjected to quenching from the upper and lower surfaces are analyzed by the photoviscoelastic technique
  • S. Sugimori
  • Y. Miyano
  • T. Kunio
Article

Abstract

This paper reports on a procedure for photoviscoelastic analysis where the axes of principal stress, principal strain and polarization of light coincide in the presence of a large temperature change. More specially, the transient-thermal stress and strain due to stress in an epoxy beam subjected to quenching from both the upper and lower surfaces, are determined using the time-temperature-equivalent law for stress, strain and birefringence. The transient-thermal stress and strain in the beam were determined experimentally using hereditary integrations from the measurement of the transient temperature and birefringence due to the quenching of the beam. The transient thermal stress and strain were also calculated theoretically using the linear-viscoelastic theory. The experimentally determined thermal stress agrees closely with the theoretical results. The experimentally determined strain agrees qualitatively with the theoretical values. Thus, it is concluded that the photoviscoelastic technique is useful in analyzing the proposed problem.

Keywords

Epoxy Mechanical Engineer Temperature Change Fluid Dynamics Thermal Stress 

List of Symbols

a

thermal diffusivity, m2/s

\(a_{T_0 } \)

time-temperature shift factor

Cε.r

relaxation birefringence-strain coefficient, fr/m

Cε.c−1

inverse-creep strain-birefringence coefficient, m/fr

Cσ.r−1

inverse-relaxation stress-birefringence coefficient, N/fr · m

c

specific heat, J/kg · °C

d

depth of specimen, m

Er

relaxation modulus, Pa

G

universal gas constant, 8.31 J/mol · K

h

thickness of specimen, m

k

thermal conductivity, W/m · °C

N

fringe order, fr

T

temperature, °C

Tc

cooling-water temperature, °C

Tg

glass-transition temperature, °C

Tq

quenching temperature, °C

T0

reference temperature, °C

t

time, min

t

reduced time, min

x,y,z

rectangular coordinates, m

ΔH

activation energy, J/mol

\(\varepsilon _t \)

thermal expansion

\(\varepsilon _\sigma \)

strain due to stress

\(\varepsilon _1 ,\varepsilon _2 \)

principal strain

λ

light wavelength, m

ν

Poisson's ratio

ϱ

density, kg/m3

\(\sigma _t \)

thermal stress, Pa

\(\sigma _1 ,\sigma _2 \)

principal stress, Pa

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References

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Copyright information

© Society for Experimental Mechanics, Inc. 1984

Authors and Affiliations

  • S. Sugimori
    • 1
  • Y. Miyano
    • 1
  • T. Kunio
    • 2
  1. 1.Materials System Research LaboratoryKanazawa Institute of TechnologyNonoichi, KanazawaJapan
  2. 2.Department of Mechanical EngineeringKeio UniversityKohoku-kuJapan

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