This document describes a project to fabricate and experimentally test a torsion test rig. The objectives are to design and fabricate an apparatus to test the torsional strength of metal workpieces and verify the modulus of rigidity. The methodology involves conceptual design, material selection, manufacturing, and experimental testing from July 2019 to February 2020. Calculations are provided to determine shear stress and modulus of rigidity from torque and angular displacement measurements during testing.

1. “Fabrication & Experimental testing of torsion Test Rig”
By
Mr. Neeraj Vinod Bodhale(71704559F)
Mr. Kshitij Abasaheb Borade(71704562F)
Mr. Harshad Deelip Chaudhari(71704717C)
Mr. Amol Anil Patil(71704981H)
Under the guidance of
Prof. M.R.BAHIRAM
B.E. (Mechanical Engineering)
[MECHANICAL ENGINEERING DEPARTMENT]
K.K.Wagh Institute of Engineering Education and
Research, Nashik
A.Y. 2019-20
1

2. CONTENT
• Problem statement
• Objective
• Introduction
• Literature Review
• Project methodology
• Model
• Calculation
• Materials Selection
• References

3. PROBLEM STATEMENT
• The statement of project is “Design And Fabrication of
apparatus for Torsion Testing.” and determine Modulus of
rigidity & shear stress.

4. OBJECTIVE
• Conceptual Drawing of Torsion Testing Rig
• Design and fabricate an experimental rig that can be used to torsional
strength of metal workpieces.
• Understand the principles of torsion testing, practice their testing skills and
interpreting the experimental results of the provided materials when failed
under torsion.
• Verify the Modulus of Rigidity with Standard Values.

5. INTRODUCTION
• Mechanical testing plays an important role in finding fundamental
properties of engineering materials.
• A machine part is said to be under torsion when it is subjected to
twisting couples or torques. A couple is formed by two forces of
equal magnitude but oppositely directed while torque is a measure
of the twisting effect of the couple on an object under the action of
the couple.
• Various mechanical components can be tested using torsion testing
rig.

6. LITERATURE REVIEW

7. Author Research paper conclusion
Mr. Rajkumar D. Patil, Prof.
P. N. Gore
Review the Effect of
Specimen Geometry on
Torsion Test Results Vol. 2,
Issue 12, December 2013
The true shear stress-strain
curve can be drawn using
modified Nadai method.
This method accounts for
length change in free-end
torsion and it is a method
to determine the true
shear stress-strain curve
without measurement of
radial and hoop strains.
Rajkumar D. Patil Uttam S.
Bongarde Vishal R. Balwan
Effect of Specimen
Dimensions on Yield Shear
Stress in Torsion Testing of
AISI 1020 Steel by using
Taguchi with GRA Vol. 5,
Issue 09, 2017
It is observed that the yield
shear stress decreases with
increase in outer diameter
and further increases
Rakesh gupta, Thomas
miller etl
Experimental evolution of
torsion test for
determining shear strength
of structure vol.3, July
2002
Evidence is convincing that
torsion method is accurate
for calculating shear
strength

8. PROJECT METHODOLOGY
MONTH PROBABLE DATE WORK
JULY 1 JULY -30 JULY
Project Selection.
AUG 1 AUG -30 AUG
Project Finalization.
SEPT 1 SEPT -30 SEPT Data Collection.
OCT 1 OCT – 30 OCT Model Concept.
NOV 1 NOV – 30 NOV Material Procurement
DEC 1DEC-31DEC Manufacturing Process.
JAN 1JAN – 30 JAN Experimental testing.
FEB 1 FEB -28 FEB Project Report.

9. TORSION
- Torsion occurs when an object, such as a bar with a cylindrical or
square cross section is twisted. The twisting force acting on the
object is known as torque, and the resulting stress is known as
Shear stress

10. First conceptual drawing

11. Second Conceptual drawing

12. SCHEMATIC DIAGRAM
Tentative Size of Frame -
1*4 Feet
Tentative Size of Testing Rod
–up to 8mm

13. COMPONENTS
• Base
• Protractor Scale
• Pulley
• Weight
• Jaws

14. CREO MODEL

16. MATERIALS SELECTION FOR BASE PLATE
Mild Steel Cast Iron
Carbon Content:-0.05-.30% Carbon Content:-2-4%
Ductile Brittle
Low Damping property as
compared to cast iron
More Damping property as
compared to cast iron
Low Machinable property as
compared to cast iron
High Machinable property as
compared to cast iron
High Melting Point Low Melting Point
Compressive and Ultimate
Tensile stress is more
Compressive and Ultimate
Tensile stress is less

17. PROCEDURE
• 1. Select the driving dogs to suit the size of the specimen and clamp it in
the machine by adjusting the length of the specimen by means of a sliding
spindle.
• 2. Measure the diameter at about three places and take the average value.
• 3. Choose the appropriate range by capacity change lever
• 4. Set the maximum load pointer to zero.
• 5. Set the protector to zero for convenience and clamp it by means of
knurled screw.
• 6. Carry out straining by attaching the mass to the string of the pulley.
• 7. Load the machine in suitable increments.
• 8. Then load out to failure as to cause equal increments of strain reading.
• 9. Plot a torque- twist (T- θ) graph.
• 10. Read off co-ordinates of a convenient point from the straight line
portion of the torque twist (T- θ) graph and calculate the value of G by
using relation
• G= T/θ×l/J

18. CALCULATION
• R.S. Khurmi & J.K. Gupta (2005) stated as in our case one end of a shaft is fixed
and other is subjected to external torque. As said earlier that stresses produce by the
torque will be zero at central axis and maximum at the outer surface. The maximum
value of this torsional stress can find out by the following formula
• τ/r= T/J
• In above equation τ is the torsional stresses produce in the shaft, r is the radius of
the shaft, T is the torque applied at the end of the shaft and J is the second polar
moment of inertia of the shaft. Second polar moment of inertia of the shaft can be
finding out by following formula where D is diameter of the shaft.
• J= (π ×D^4)/32
• This first equation can be rewritten in the form of angular displacement, modulus of
rigidity and length of shaft and follow.
• τ/r= Gθ/l
• In above equation G is the modulus of rigidity, l is the length if the shaft and θ is the
angular displacement as a result of applied torque. First and third equation can be
combined to an equation through which we can find the modulus of rigidity of any
material under observation. G= T/θ×l/J

20. REFERENCES:-
1. R.S.Khurmi, J.k. Gupta,Machine Design, multicolor updated ed.,S.Chand&
Company Ltd., New Delhi, 2006.
2. American Standard for Testing Materials, 1986. Standard Test Method for
Shear Modulus at Room Temperature. ASTM Designation E143-61, 1986.
1986 Annual Book ASTM Standard.ect
3. Rajput, R. K., 2006. Strength of Materials. 1st Multicolour illustrative
Revised Ed. S. Chand & Company Ltd, New Delhi.
4. Review the Effect of Specimen Geometry on Torsion Test Results, Mr.
Rajkumar D. Patil, Prof. P. N. Gore, International Journal of Innovative
Research in Science, Engineering and Technology, Vol. 2, Issue 12,
December 2013,pp.7567-7574.
5. The Role/Importance of Engineering Materials Utilization in Present Day
World Engr. Obassi Ettu, International Journal of Engineering
Development and Research IJEDR , 2014,Volume 3, Issue , ISSN: 2321-
9939.pp.308-323.

21. URL
• http://www.fuelinstrument.com/torsion-erichsen-test.pdf
• http://www.ijirset.com/upload/2013/december/61_Review.pdf
• http://www.cof.orst.edu/cof/wse/faculty/gupta/PDF/Experimental
%20Evaluation%20of%20the%20Torsion%20Test%20for%20Determi
ning%20Shear%20Strength%20of%20Structural%20Lumber.pdf
• http://nvlpubs.nist.gov/nistpubs/jres/61/jresv61n3p149_A1b.pdf
• http://digital.lib.lehigh.edu/fritz/pdf/209_1.pdf
• http://gyan.fragnel.ac.in/~siddesh/manual.pdf
• http://www.citchennai.edu.in/wp-
content/uploads/2014/01/Strength-of-Materials-Lab.pdf
• http://jnec.org/Lab-manuals/CIVIL/SOM%20Lab%20Manual.pdf

22. Thank you