1. 3 – D photoelasticity

2. Stress Freezing

3. Molecular structure in an Epoxy

4. 3 – D photoelasticity
Disc under diametric compression

6. 3 – D photoelasticity
Effect of Machining in stress freezed
model

7. 3 – D photoelasticity

8. Model fabrication and Loading
• 3-D model of the joint comprising a ball insert
, base ring bush base ring block are fabricated
by using Epoxy resin (ArlditeCY-230) and
hardener (HY-951).
• The fabricated parts are assembled and
loaded and stress frozen.

9. Model fabrication and stress freezing
• A suitable force is applied using dead weight
along the ball centre.
• After stress freezing, the slices are cut from
the stress frozen model along the loading
plane, where the stress is maximum.

10. Stress Freezing

11. Central Slice

12. Integrated Photoelasticity

13. Principle of optical equivalence
• The retarder introduces the retardation equivalent
to the one introduced by 3-D model.
• The azimuth of the exit light ellipse may not be
the same as that for for a 3-D model.the necessary
correction is done by the rotater.
• The parameters representing the retarder and
rotater are the experimental parameters to be
determined in integrated photoelasticity.

15. Principle of optical equivalence
• The retardation is termed as characteristic
retardation and denoted by 2∆
• The orientation of the retarder is termed as
the primary characteristic direction denoted
by the symbol θ.
• An idealised optical element, which simply
rotates the azimuth of the light ellipse is
specified by the angular rotation γ

16. Principle of optical equivalence
• The angle γ is termed as characteristic
rotation.
• the summary is as follows:
• Once the retardation and rotation is known at
the point of interest, jones matrix can be
constructed.
• Suppose take problem in which stress
distribution is known along the light path.

17. Integrated photoelasticity
• Then analytically jones matrix can be written
for each of the planes and multiply of them.
• This gives the final jones matrix and compare
this with the jones matrix which is written
from experimental values and find the
parameters related to stress distribution.

18. Integrated photoelasticity
• So we need to assume stress distribution field
reasonably well with several coefficients, and
find the necessary number of equations equal
to coefficients.
• Hence we need multiple optical paths and
multiple collection of charecteristic
parameters so it becomes mathematically
intensive.