Experimental stress analysis is useful in many situations to analyze stresses. It has several merits over theoretical analysis alone, including the ability to validate theoretical models and account for real-world complexities. Two common methods are electrical resistance strain gauges and optical strain gauges. Electrical resistance strain gauges convert measured strain into a proportional output voltage based on the gauge's resistance and factor. Optical strain gauges like the Tuckerman gauge use polarized light and stress-induced birefringence to visualize strain patterns.

1. Code: 12D20105a
M.Tech I Semester Supplementary Examinations September/October 2015
EXPERIMENTAL STRESS ANALYSIS
(Common to St.E and CP&M)
(For students admitted in 2011, 2012, 2013 & 2014 only)
Time: 3 hours Max. Marks: 60
Answer any FIVE questions
All questions carry equal marks
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1 Explain the merits and uses of experimental stress analysis. Explain the various situations in
which experimental stress analysis may be useful to the stress analyst.
2 Explain the characteristics of an ideal strain gauge. Also explain the working of Tuckerman
optical strain gauge with the help of a neat diagram.
3 (a) Explain the principle of strain measurement and advantages of electrical resistance strain gauge.
(b) A single strain gauge set-up consists of gauge resistance = 100 , gauge factor = 2.1, EBB = 12
volts and E for the specimen = 2.1 x 106
kg/cm2
. As force F fluctuates the bending stress at the
gauge varies from 0 to 1600 kg/cm2
. Determine the output voltage.
4 The following readings of strain were obtained on a rectangular strain rosette mounted on
aluminium for which E = 70 GPa, ,
Determine the principal strain, principal strain directions, principal stresses and maximum shear
stress.
5 Explain in detail the ultrasonic pulse velocity method. And also explain its application to concrete.
6 (a) Explain the text procedures for Brittle-coating analysis.
(b) Explain the failure theories in Brittle coating.
7 Explain the effects of a stressed model in a plane polariscope.
8 Write short notes on:
(a) Materials for two dimensional photo elasticity.
(b) Properties of commonly employed photo elastic materials.
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