The document provides instructions for conducting various materials testing experiments, including hardness, impact, tension, torsion, bending, shear, and compression tests. The Rockwell hardness test and Brinell hardness test experiments are described in detail, outlining the objectives, required materials and equipment, safety precautions, procedures, observations, calculations, and results. The impact test experiment overview explains the theory behind impact testing using the Izod and Charpy tests to determine a material's resistance to impact loads.
Tensile, Impact and Hardness Testing of Mild SteelGulfam Hussain
The main purpose of this report is to study the mechanical properties and
failure mode of mild steel. Three types of standard tests i.e. tensile test, impact
test, and hardness test were conducted on the standard specimens of mild steel.
From the tests, results were obtained; Tensile strength, Impact strength, and
hardness were calculated. It was observed that Tensile Strength, Impact Strength
and Hardness of MS specimen were 1450.833 N/mm², 29.5 J & 59.25 HRB.
Tensile, Impact and Hardness Testing of Mild SteelGulfam Hussain
The main purpose of this report is to study the mechanical properties and
failure mode of mild steel. Three types of standard tests i.e. tensile test, impact
test, and hardness test were conducted on the standard specimens of mild steel.
From the tests, results were obtained; Tensile strength, Impact strength, and
hardness were calculated. It was observed that Tensile Strength, Impact Strength
and Hardness of MS specimen were 1450.833 N/mm², 29.5 J & 59.25 HRB.
Strength of material lab, Exp 3&4: Compression and impact testsOsaid Qasim
- Utilization the UTM machine and know the different
ways that could test the material’s properties.
2- Knowing the different types of failure in the compression.
3- Determining Young's modulus “E” and Passion’s ratio
“υ” and Yield/Proof stress σ y.
1. Finding the impact load effect on the materials.
2. Finding the relative toughness of the different materials.
3. Distinguish between static and dynamic loads and how differently they
effect in the material.
4.Knowing the different methods to preform the impact test (Charpy,
IZOD, Impact tensile).
In the material testing laboratory, Tensile test was done on a mild steel specimen as figure 4 to identify the young’s modulus, ultimate tensile strength, yield strength and percentage elongation. The results were as table 1
This presentation is for mechanical engineering/ civil engineering students to help them understand the different type of destructive mechanical testing of materials. The tensile testing, hardness, impact test procedures are explained in detail.
Strength of material lab, Exp 3&4: Compression and impact testsOsaid Qasim
- Utilization the UTM machine and know the different
ways that could test the material’s properties.
2- Knowing the different types of failure in the compression.
3- Determining Young's modulus “E” and Passion’s ratio
“υ” and Yield/Proof stress σ y.
1. Finding the impact load effect on the materials.
2. Finding the relative toughness of the different materials.
3. Distinguish between static and dynamic loads and how differently they
effect in the material.
4.Knowing the different methods to preform the impact test (Charpy,
IZOD, Impact tensile).
In the material testing laboratory, Tensile test was done on a mild steel specimen as figure 4 to identify the young’s modulus, ultimate tensile strength, yield strength and percentage elongation. The results were as table 1
This presentation is for mechanical engineering/ civil engineering students to help them understand the different type of destructive mechanical testing of materials. The tensile testing, hardness, impact test procedures are explained in detail.
1. OBJECT
The hardness test is a mechanical test for material properties which are used in engineering
design, analysis of structures, and materials development. The principal purpose of the
hardness test is to determine the suitability of a material for a given application, or the
particular treatment to which the material has been subjected. The ease with which the
hardness test can be made has made it the most common method of inspection for metals and
alloys.
Executive Directors Chat Leveraging AI for Diversity, Equity, and InclusionTechSoup
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A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
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June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
1. 1
___________________________________________
Strength of materials
Lab. Manual
______________________________________________________________________________________________
Production Engineering
2. 2
Strength of materials lab. manual
_________________________________________________________________
Contents
___________________________________________________________________
S.No. Title Pg.no
_________________________________________________________________
1. Rockwell Hardness test 3
2. Brinell hardness test. 5
3. Impact test 8
4. Tension test 14
5. Torsion test 19
6. Bending test 21
7. Shear test 24
8. Compression test 26
________________________________________________________________
Instructions.1.Write observations, tables, diagrams, Specimen calculations
in the blank left side of the journal and others to the right.
3. 3
Experiment No.1
_________________________________________________________________
Title Rockwell Hardness test
Objective To determine the hardness the Hardness of the given
Specimen using Rockwell hardness test.
Materials and equipments required
Rockwell hardness testing machine.
Black diamond cone indenter,
Hard steel specimen.
Theory
Rockwell test is developed by the Wilson instrument co U.S.A in 1920.
This test is an indentation test used for smaller specimens and harder materials.
The test is subject of IS: 1586.In this test indenter is forced into the surface of a
test piece in two operations, measuring the permanent increase in depth of an
indentation from the depth increased from the depth reached under a datum load
due to an additional load.
Measurement of indentation is made after removing the additional load. Indenter
used is the cone having an angle of 120 degrees made of black diamond.
Precautions
1. Thickness of the specimen should not be less than 8 times the depth of
indentation to avoid the deformation to be extended to the opposite surface of a
specimen.
2. Indentation should not be made nearer to the edge of a specimen to avoid
unnecessary concentration of stresses. In such case distance from the edge to
the center of indentation should be greater than 2.5 times diameter of
indentation.
3. Rapid rate of applying load should be avoided. Load applied on the ball may rise
a little because of its sudden action. Also rapidly applied load will restrict plastic
flow of a material, which produces effect on size of indentation.
Procedure
1. Examine hardness testing machine (fig.1).
2. Place the specimen on platform of a machine. Using the elevating screw raise
the platform and bring the specimen just in contact with the ball. apply an initial
load until the small pointer shows red mark.
3. Release the operating valve to apply additional load. Immediately after the
additional load applied, bring back operating valve to its position.
4. Read the position of the pointer on the C scale, which gives the hardness
number.
4. 4
5. Repeat the procedure five times on the specimen selecting different points for
indentation.
Observation
1. Take average of five values of indentation of each specimen. Obtain the
hardness number from the dial of a machine.
2. Compare Brinell and Rockwell hardness tests obtained.
Figure .1
Rockwell hardness test equipment
Result
Rockwell hardness of given specimen is
5. 5
Experiment No.2
________________________________________________________________
Title Brinell hardness test.
Aim To determine the hardness of the given specimen using Brinell hardness
test.
Specimen and specimen
Brinell hardness tester (fig.2)
Aluminum specimen
Ball indenter.
Precautions
1. Thickness of the specimen should not be less than 8 times the depth of
indentation to avoid the deformation to be extended to the opposite surface of
a specimen.
2. Indentation should not be made nearer to the edge of a specimen to avoid
unnecessary concentration of stresses. In such case distance from the edge to
the center of indentation should be greater than 2.5 times diameter of
indentation.
3. Rapid rate of applying load should be avoided. Load applied on the ball may
rise a little because of its sudden action. Also rapidly applied load will restrict
plastic flow of a material, which produces effect on size of indentation.
4. Surface of the specimen is well polished, free from oxide scale and any foreign
material.
Theory
Hardness of a material is generally defined as Resistance to the permanent
indentation under static and dynamic load. When a material is required to use
under direct static or dynamic loads, only indentation hardness test will be useful
to find out resistance to indentation.
In Brinell hardness test, a steel ball of diameter (D) is forced under a load (F) on to
a surface of test specimen. Mean diameter (d) of indentation is measured after the
removal of the load (F).
Observation
1. Take average of five values of indentation of each specimen. Obtain the
hardness number from equation (!).
2. Compare Brinell and Rockwell hardness tests obtained.
Procedure
6. 6
1.Load to be applied for hardness test should be selected according to the
expected hardness of the material. However test load shall be kept equal to 30
times the square of the diameter of the ball (diameter in mm)
2
F=30.D
Where ball diameter, generally taken as 10 mm.
For guidelines hardness range for standard loads given below
Ball diameter Load (kg) Range of Brinell hardness
10 3000 96 to 600
1500 48 to 300
500 16 to 100
2.Apply the load for a minimum of 15 seconds to 30 seconds. [if ferrous
metals are to be tested time applied will be 15 seconds and for softer metal 30
seconds]
3.Remove the load and measure the diameter of indentation nearest to 0.02 mm
using microscope (projected image)
4.Calculate Brinell hardness number (HB). As per IS: 1500.
5.Brinell hardness number
2 F
(1)
[
p D D - D 2
- d 2
]
where D is the diameter of ball indenter and d is the diameter of indentation.
Hardness numbers normally obtained for different materials are given below
(under 3000 kg and 10 mm diameter ball used)
Ordinary steels medium 100 to 500
carbon
130 to 160
Structural steel
800 to 900
Very hard steel
Note: Brinell test is not recommended for then materials having HB over 630.
It is necessary to mention ball size and load with the hardness test when standard
size of ball and load are not used. Because indentation done by different size of
ball and load on different materials are not geometrically similar. Ball also
8. 8
Experiment No.3
_______________________________________________________________________
Title Impact test
Aim To determine the Impact toughness (strain energy) through
Izod test and Charpy test
Theory
In a impact test a specially prepared notched specimen is fractured by a single
blow from a heavy hammer and energy required being a measure of resistance to
impact.
Impact load is produced by a swinging of an impact weight W (hammer) from a
height h. Release of the weight from the height h swings the weight through the arc
of a circle, which strikes the specimen to fracture at the notch (fig..
2
Kinetic energy of the hammer at the time of impact is mv /2, which is equal to the
relative potential energy of the hammer before its release. (mgh),where m is the
mass of the hammer and v = 2 gh is its tangential velocity at impact, g is
2
gravitational acceleration (9.806 m/s ) and h is the height through which hammer
falls. Impact velocity will be 5.126 m/s or slightly less.
Here it is interesting to note that height through which hammer drops determines
the velocity and height and mass of a hammer combined determine the energy.
Energy used can be measured from the scale given. The difference between
potential energies is the fracture energy. In test machine this value indicated by
the pointer on the scale. If the scale is calibrated in energy units, marks on the
scale should be drawn keeping in view angle of fall () and angle of rise (. Height h1
and h2 equals,
h1= R (1cos q) and h2= (1cos q).
With the increase or decrease in values, gap between marks on scale showing
energy also increase or decrease. This can be seen from the attached scale with
any impact machine.
Energy used in fracturing the specimen can be obtained approximately as
Wh1Wh2
This energy value called impact toughness or impact value, which will be
measured, per unit area at the notch.
Izod introduced Izod test in 1903. Test is as per the IS: 1598
Charpy introduced Charpy test in 1909. Test is as per the IS: 1499.
9. 9
a. Izod test
Specimen and equipment
1. Impact testing machine.(fig.3)
2. Specimen and v notch is shown in the fig.4. Size of the specimen is 10mm
X 10mm X 75mm
Mounting of the specimen:
Specimen is clamped to act as vertical cantilever with the notch on tension side.
Direction of blow of hammer is shown in fig. (). Direction of blow is shown in fig
Figure. 3.a
Izod Impact testing equipment
10. 10
Figure 3.b
Schematic impact testing
Figure 4
Position of specimen for Izod test
11. 11
Procedure
1. Measure the dimensions of a specimen. Also, measure the dimensions of
The notch.
2. Raise the hammer and note down initial reading from the dial, which will be
energy to be used to fracture the specimen.
3. Place the specimen for test and see that it is placed center with respect to
hammer. Check the position of notch.
4. Release the hammer and note the final reading. Difference between the
initial and final reading will give the actual energy required to fracture the
Specimen.
5. Repeat the test for specimens of other materials.
6. Compute the energy of rupture of each specimen.
Observation
Initial and final reading of the dial.
Result Strain energy of given specimen is
b. Charpy test
Specimen and equipment:
1. Impact testing machine. (Fig.6)
2. U notch is cut across the middle of one face as shown in (fig.5).
Figure 5
Specimen for Charpy test
12. 12
Figure 6
Charpy impact testing equipment
Mounting of specimen
Specimen is tested as a beam supported at each end (fig.7). Hammer is allowed to
hit then specimen at the opposite face behind the notch.
Figure.7
Mounting of specimen
13. 13
Procedure
1. Measure the dimensions of a specimen. Also, measure the dimensions of
The notch.
2. Raise the hammer and note down initial reading from the dial, which will be
energy to be used to fracture the specimen.
3. Place the specimen for test and see that it is placed center with respect to
hammer. Check the position of notch.
4. Release the hammer and note the final reading. Difference between the
initial and final reading will give the actual energy required to fracture the
Specimen.
5. Repeat the test for specimens of other materials.
6. Compute the energy of rupture of each specimen.
Observation
Initial and final reading of the dial.
Result Strain energy of given specimen is
15. 15
Figure.7b
Theory
The tensile test is most applied one, of all mechanical tests. In this test ends of a
test piece are fixed into grips connected to a straining device and to a load
measuring device. If the applied load is small enough, the deformation of any solid
body is entirely elastic. An elastically deformed solid will return to its original
position as soon as load is removed. However, if the load is too large, the material
can be deformed permanently. The initial part of the tension curve (fig.8), which is
recoverable immediately after unloading, is termed as elastic and rest of the curve,
which represents the manner in which solid undergoes plastic deformation is
termed plastic. the stress below which the deformation is essentially entirely elastic
is known as the yield strength of material. In some materials (like mild steel) the
onset of plastic deformation is denoted by a sudden drop in load indicating both an
upper and lower yield point. However, some materials do not exhibit a sharp yield
point. During plastic deformation, at larger extensions strain hardening cannot
compensate for the decrease in section and thus the load passes trough a
maximum and then begins to decrease. As this stage the’ Ultimate strength ‘, which
is defined as the ratio of the specimen to original cross –sectional area, reaches a
maximum value. Further loading will eventually cause ‘neck’ formation and rupture.
Usually a tension test is conducted at room temperature and the tensile
load is applied slowly. During this test either round or flat specimens (fig.7) may be
used. The round specimens may have smooth, shouldered or threaded ends. The
load on the specimen is applied mechanically or hydraulically depending on the
type of testing machine.
Figure. 8
16. 16
Stressstrain diagram
Procedure
1. Measure the dimensions of a specimen
Diameter=d= ,
Total length of a specimen,
Cross sectional area = Ao= ,
Mark gage length (Lo) at three different portions on the specimen,
covering effective length of a specimen.(this is required so that
necked portion will remain between any two points of gage length
on the specimen.)
2. Grip the specimen in the fixed head of a machine. (Portion of the specimen
has to be gripped as shown in the fig.7.
3. Fix the extensometer within the gauge length marked on the specimen.
Adjust the dial of extensometer at zero.
4. Adjust the dial of a machine to zero, to read load applied.
5. Select suitable increments of loads to be applied so that corresponding
elongation can be measured from dial gauge.
6. Keep speed of machine uniform. Record yield point, maximum load point,
point of breaking of specimen.
7. Remove the specimen from machine and study the fracture observes type
of fracture.
8. Measure dimensions of tested specimen. Fit the broken parts together and
measure reduced diameter and final gage length.
Observations
Specimen prepared from M.S bar/CI/Al
1. Diameter = d = mm
17. 17
2. Gage length (lo)= 5Xd= mm
3. Original cross sectional area of the specimen
2
= Ao = mm
4. Final gage length obtained= Lo’=
5. Final diameter obtained = mm
Observation table 1
Sr. Load applied (N) Area of a Stress Modulus of
2
No (p) specimen N/mm elasticity (E)
2
(Ao) N/mm
Observation table 2.
Sr. Contraction in Deformation Lateral Linear Poisson
No diameter (dd) in length strain strain ratio
(mm) (mm)
Note
1. Use vernier caliper to measure diameter, gage length etc. for the specimen.
2. If C.I. specimen is to be tested only one observation will be taken at failure.
Results
1. Calculate stress and strain for every interval of applied load.
Draw stressstrain curve as shown in the Fig.()
2. Compute the following;
a. Modulus of elasticity
Hook’s law states that stress is always proportional to strain within elastic
limit. The ratio of stress and strain is constant, called modulus of elasticity
or young’s modulus (E)
E= Stress/strain =Constant=E= ,
b. Yield stress (fy);
The point, at which strain increases without increase in stress, is known as
Yield point. Stress measured at yield point is called yield stress.
c. Tensile strength:
Maximum carrying capacity of a material in tension is called tensile
18. 18
strength
Tensile strength= maximum tensile load/ original cross sectional
Area.
d. Percentage elongation:
The extension produced in a gage length, expressed as a percentage
of its original value(LO)
% Elongation=[(LO’ – Lo)/Lo] X 100
where Lo’ is final gage length after fracture.
e. Percentage reduction in area:
= [(Ao Ao’)/Ao ] X100
where Ao’ is final reduced cross sectional area after fracture.
19. 19
Experiment No.5
Title Torsion test
Aim: To find the modulus of rigidity.
Specimen and equipments
1. A torsion testing apparatus,
2. Standard specimen of mild steel or cast iron.
3. Twist meter for measuring angles of twist
4. A steel rule and calipers and micrometer.
Figure.9.
Torsion equipment
Theory
A torsion test is quite instrumental in determining the value of rigidity (ratio of shear
stress to shear strain) of a metallic specimen. The value of modulus of rigidity can
be found out through observations made during the experiment by using the torsion
equation:
T C q Tl
= or C =
I p l I q
Where T=torque applied,
Ip= polar moment of inertia,
C=modulus of rigidity,
= Angle of twist (radians), and
l= gauge length.
20. 20
In the torque equipment refer fig. One end of the specimen is held by a fixed
support and the other end to a pulley. The pulley provides the necessary torque to
twist the rod by addition of weights (w). The twist meter attached to the rod gives the
angle of twist.
Procedure
1. Prepare the testing machine by fixing the two twist meters at some constant
lengths from fixed support.
2. Measure the diameter of the pulley and the diameter of the rod.
3. Add weights in the hanger stepwise to get a notable angle of twist for T1
and T2
4. Using the above formula calculate C
Conclusion:
Result
Modulus of rigidity of the shaft
21. 21
Experiment No.6
______________________________________________________________________
Title Bending test
Aim To find the values of bending stresses and young’s modulus of the
material of a beam (say a wooden or steel) simply supported at the
ends and carrying a concentrated load at the center.
Material and equipment
1. Universal testing machine
2. Beam of different cross sections and materials (say wood or steel)
Figure.10
Specimen details and mounting
Theory
If a beam is simply supported at the ends and carries a concentrated load at the
center, the beam bends concave upwards. The distance between the original
position of the beam and its position after bending is different at different points (fig)
along the length if the beam, being maximum at the center in this case. This
difference is called ‘deflection’.
In this type of loading the maximum amount of deflection () is given by the relation,
Wl 3
d =
Ei
48
22. 22
or
Wl 3
E =
EI
48
Where W= load acting at the center, N
l=length of the beam between the supports, mm
2
E=young’s modulus of material of the beam, N/mm
I=second moment of area of the cross section (moment of inertia) of the beam,
4
about the neutral axis, mm
Bending stress:
As per bending equation,
M s b
=
I y
Where M= bending moment, Nmm
4
I= moment of inertia, mm
2
s b =Bending stress, N/mm
y=distance of the fiber of the beam from the neutral axis.
Observation
Refer Fig.
Width of the beam=………mm (for rectangular cross section)
Depth of the beam D=…mm (for circular cross section)
3 4
Moment of inertia of rectangular section= bd /12=………mm
4
Moment of inertia of circular section =………mm
Initial reading of the vernier= ….mm
(It should be subtracted from the reading taken after putting the load)
S. Load Bending Bending stress Deflection Young’s modulus
No W(N) moment My d (mm) of elasticity
sb = ( N / mm 2 )
I
Wl Wl 3
M = ( N - mm 3 )
4 E= 2
(N/mm )
dI
48
Precautions
1. Make sure that the beam and load is placed at the proper position.
2. Cross section of the beam should be large
3. Note down the readings of the vernier scale carefully.
23. 23
Procedure
1. Adjust the supports alone the UTM bed so that they are symmetrically with
respect to the length of the bed
2. Place the beam on the knifeedges on the blocks so as to project equally
beyond each knifeedge. See that the load is applied at the center of the
beam.
3. Note the initial reading of vernier scale.
4. Apply a load and again note the reading of the vernier scale.
5. Go on taking reading applying load in steps each time till you have
minimum 6 readings.
6. Find the deflection (d) in each time by subtracting the initial reading of
vernier scale.
7. Draw a graph between load (W) and deflection (d). On the graph choose
any two convenient points and between these points find the corresponding
Wl 3
values of W and d. Putting these values in the relation E =
d I
48
Calculate the value of E.
My
8. Calculate the bending stresses for different loads using relation b =
s as
I
given in the observation table.
9. Repeat the experiment for different beams.
Result
a. Bending stress………..units
b. Young’s modulus………units
24. 24
Experiment No.7
_______________________________________________________________________
Title Shear test
Aim To find the shear strength of given specimen
Material and Equipment
1. Universal testing machine
2. Shear test attachment
3. Given specimen
Figure
Shearing fixture
Observation
Diameter of the pin d= ….mm
Cross sectional area of the pin(in double shear)
2 2
= 2 X p/4 Xd =…. mm
Load taken by the specimen at the time of failure, W =. ……(N)
Strength of the pin against shearing (t)
W
4
t= 2
=… N/mm
2 d 2
p
25. 25
Procedure
1. Insert the specimen in position and grip one end of the attachment in the
upper portion and one end in the lower position
2. Switch on the UTM
3. Bring the drag indicator in contact with the main indicator.
4. Select the suitable range of loads and space the corresponding weight in
the pendulum and balance it if necessary with the help of small balancing
weights
5. Operate (push) the button for driving the motor to drive the pump.
6. Gradually move the head control ever in left hand direction till the specimen
shears.
7. Note down the load at which the specimen shears.
8. Stop the machine and remove the specimen.
Repeat the experiment with other specimens.
Precautions
1. The measuring range should not be changed at any stage during the test.
2. The inner diameter of the hole in the shear stress attachment should be
slightly grater than the specimen.
3. Measure the diameter of the specimen accurately.
Result.
2
Shear strength of the specimen ………N/mm
26. 26
Experiment No. 8
_______________________________________________________________________
Title Compression test
Aim To find the compressive strength of given specimen.
Material and Equipment
Universal testing machine,
Compression pads,
Given specimen,
Theory
This is the test to know strength of a material under compression. Generally
compression test is carried out to know either simple compression characteristics
of material or column action of structural members.
It has been observed that for varying height of member, keeping crosssectional
and the load applied constant, there is an increased tendency towards bending of
a member.
Member under compression usually bends along minor axis, i.e, along least lateral
dimension. According to column theory slenderness ratio has more functional
value. If this ratio goes on increasing, axial compressive stress goes on
decreasing and member buckles more and more. End conditions at the time of
test have a pronounced effect on compressive strength of materials. Effective
length must be taken according to end conditions assumed, at the time of the test.
As the ends of the member is made plain and fit between two jaws of the machine,
fixed end is assumed for calculation of effective length. Effective length is taken as
0.5 L where L is actual length of a specimen
Figure
27. 27
Observation
2
Cross sectional area of the specimen perpendicular to the load=A=……mm
Load taken by the specimen at the time of failure, W=. ……(N)
2
Strength of the pin against shearing (s) = [W/A ] N/mm
Procedure
1. Place the specimen in position between the compression pads.
2. Switch on the UTM
3. Bring the drag indicator in contact with the main indicator.
4. Select the suitable range of loads and space the corresponding weight in
the pendulum and balance it if necessary with the help of small balancing
weights
5. Operate (push) the button for driving the motor to drive the pump.
6. Gradually move the head control ever in left hand direction till the specimen
fails.
7. Note down the load at which the specimen shears
8. Stop the machine and remove the specimen.
9. Repeat the experiment with other specimens.
Precautions
1. Place the specimen at center of compression pads,
2. Stop the UTM as soon as the specimen fails.
3. Cross sectional area of specimen for compression test should be kept large
as compared to the specimen for tension test: to obtain the proper degree
of stability.
Result
2
Compressive strength of the specimen ………N/mm