No. of Pages: 2
AP] ABDUL KALAM TECHNOLOGICAL UNIVERSITY

SECOND SEMESTER M.TECH DEGREE EXAMINATION, DECEMBER 2018

Branch: Mechanical

Stream(s): Machine Design

OIME6106: EXPERIMENTAL STRESS ANALYSIS

Answer any twofull questions from each part
(Nine marks for each question in Parts A &B and Twelve marks for each question in Part C)
Limit answers to the required points,

Max. Marks: 60 Duration: 3 hours
PART A

1. ೩. A two dimensional stress state, ff z ച്‌ Tzy = O exists at a point on the surface of
a loaded member. The remaining stress components are = 90 MPa, ० = 40 MPa,
and 00 MPa. Determine the Principal stresses, Principal directions and
maximum shear stress at the point.

b. Graphically illustrate the solution to above problem using Mohr's circle

c. Explain the necessity of strain compatibility conditions in experimental stress
analysis

2. a. Explain briefly working of any one type each of mechanical and optical strain gauge

b. Explain the characteristics (a) gauge factor (b) gauge sensitivity (b) gauge
transverse sensitivity of electrical strain gauges

3. a. Explain the residual stress measurement method using strain gauges

४. Calculate Principal strains/stresses and maximum shear stress and their directions
on a steel plate (E=200 GPa, 0=0.3), if Delta rosette give the following readings:
-250 um/ m, um/m, -200 urn/m.
PART 8
4. ೩ Prove that the maximum bridge sensitivity of an unbalanced

constant voltage Wheatstone bridge with four active gauges is VF
where F—gauge factor and V=voltage applied

b. Explain the method of achieving temperature compensation using three lead
wire system for st-rain gauge analysis