Strength of Material Lab Manual
Strength of Material Lab Manual
Strength of Material Lab Manual
Technology, Bhopal
STRENGTH OF
MATERIALS LAB
LIST OF EXPERIMENTS
Experiment No. 1
AIM: To study the Universal Testing Machine (UTM).
OBJECT: To Study the various components of the Universal Testing Machine (UTM) & test
procedures of various practical‟s to be performed.
APPARATUS USED: - Universal Testing Machine with all attachment i.e. shears test
attachment, bending attachment, tension grips, compression test attachment etc.
DIAGRAM:
(a)
(b)
(c)
METHOD OF TESTING:-
Initial Adjustment: before testing adjust the pendulum with respect to capacity of the test i.e.
8 Tones; 10 Tones; 20 Tones; 40 Tones etc.
For ex: - A specimen of 6 tones capacity gives more accurate result of 10 Tones capacity range
instead of 20 Tones capacity range. These ranges of capacity are adjusted on the dial with the
Experiment No. 2
AIM: To perform a tensile test of mild steel specimen on Universal Testing Machine.
OBJECT: To conduct a tensile test on a mild steel specimen and determine the following:
1) Limit of proportionality
2) Elastic limit
3) Yield strength
4) Ultimate strength
5) Young‟s modulus of elasticity
6) Percentage elongation
7) Percentage reduction in area.
APPARATUS USED:
1) Universal Testing Machine (UTM)
2) Mild steel specimens
3) Graph paper
4) Scale
5) Vernier Caliper
DIAGRAM:
(a)
(b)
(c)
OBESERVATION:
Material:
Original dimensions
Length: …………………..
Diameter: …………………
Area: ………………………
Final dimensions
Length: …………………..
Diameter: …………………
Area: ………………………
OBESERVATION TABLE:
S.
No.
Load
(N)
Original
Length
Extension
(mm)
Stress
Load N
Area m
2 Strain
Change in length
Original length
(mm)
Load at elasticlimit N
2) ElasticLimit
Originalarea of cross - section mm 2
Yield Load N
3) Yield Strength
Originalarea of cross - section mm 2
RESULT:
1) Average Breaking Stress =
2) Ultimate Stress =
3) Average % Elongation =
PRECAUTIONS:
1) If the strain measuring device is an extensometer it should be removed before
necking begins.
2) Measure deflection on scale accurately & carefully.
Experiment No. 3
AIM: To determine the shear strength of mild steel on Universal Testing Machine
W
Shear Strength of rod = N/mm 2
π 2
2 d
4
RESULT:
The Shear strength of mild steel specimen= …………….. N/mm2
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 greater
than that of the specimen.
3) Measure the diameter of the specimen accurately.
Experiment No. 4
AIM: To perform bending test on Universal Testing Machine (UTM).
OBJECT: To determine the deflection of given beam specimen.
APPARATUS USED:
1) UTM (Beam apparatus)
2) Bending fixture
3) Vernier caliper
4) Specimen
5) Dial gauge.
DIAGRAM:
1) Measure the length, width and thickness of test piece, by vernier caliper.
2) Place the bending fixture on the lower cross head of the testing m/c.
3) Place the test piece on the rollers of the bending fixture.
4) By loading the dial gauge in a stand, make its spindle knob the test piece.
5) Start the m/c and note down the load and dial gauge readings.
6) Plot the graph between load and deflection.
OBSERVATION:
bt 3
1) I
12
FL3
2) δ
48EI
RESULT: The deflection of beam is ………… mm
PRECAUTIONS:
1) Test piece should be properly touching the fixture. Test piece should be straight.
2) Take reading carefully.
3) Elastic limit of the beam should not be exceeded.
Experiment No. 5
AIM: To determined impact strength of steel.
THEORY: An impact test signifies toughness of material that is ability of material to absorb
energy during plastic deformation. Static tension tests of un-notched specimens do not always
reveal the susceptibility of a metal to brittle fracture.
RESULT:
The energy absorbed for Mild Steel is found out to be ……………… Joules.
Experiment No. 6
AIM: To determined impact strength of steel.
THEORY: An impact test signifies toughness of material that is ability of material to absorb
energy during plastic deformation. Static tension tests of unmatched specimens do not always
PROCEDURE:
Following steps are involved to conduct charpy impact test:-
6) Lift the hammer to an appropriate knife edge position and note the energy stored in the
hammer. For the standard charpy test the energy stored should be 164 joules. Bring the
striking hammer to its top most striking position unless it is already there, and lock it at
that position.
7) Bring indicator of the machine to zero, or follow the instructions of the operating
manual supplied with the machine.
8) Release the hammer. It will fall due to gravity and break the specimen through its
momentum, the total energy is not absorbed by the specimen. Then it continues to
swing. At its topmost height after breaking the specimen, the indicator stops moving,
while the pendulum falls back. Note the reading of indicator at that topmost final
position (Residual energy).
9) Impact strength of the test specimen is the difference of the initial energy stored
in hammer and the residual energy.
10) Again bring back the hammer to its idle position and back.
OBESERVATION:
Initial Energy (E1) = …………………….… Joule
Residual Energy (E2) = …………………… Joule
RESULT:
The energy absorbed for Mild Steel is found out to be ……………… Joules.
Experiment No. 7
AIM: To Conduct the hardness test on Rockwell Hardness Tester.
OBJECT: To determine the hardness no. of mild steel, carbon steel, brass and aluminum
specimens.
APPARATUS USED:
Hardness tester, mild steel, carbon steel, brass and aluminum specimens.
DIAGRAM:
Experiment No. 8
AIM: To Conduct the hardness test on Vickers Hardness Tester.
OBJECT: To determine the hardness no. of mild steel, carbon steel, brass and aluminum
specimens.
APPARATUS USED: Vickers Hardness Tester, mild steel, carbon steel, brass and aluminum
specimens.
DIAGRAM:
THEORY: The test utilizes the depth of indentation under standard loading condition as
measure of hardness. The test load applied to the surface area „P‟ form a permanent
impression. The Vicker‟s indenture is a diamond pyramid with square base and
included angle between opposite faces as 136. The impression of this indentor has square
boundary with depression inside. The length of two diagonals is measured under microscope
and average is used to calculate the surface area of indentation.
136o
2FSin
HV 2
d2
F
HV 1.854 (9.1)
d2
Where F is the load in Kgf, d is average length of two diagonals.
d 1 d 2
Mean diagonal of indentation, d
2
F
Vickers hardness = HV 1.854 = ……………HV
d2
Note: - The Vickers Hardness value is always mentioned with reference to load applied. For
example 610HV30 Or HV30 = 610 where 30 denotes the load applied is 30 Kgf.
RESULT:
The Vickers Hardness value of the given specimen is……………HV
PRECAUTIONS:
1) The surface to be tested should be clean, dry and smooth.
2) The surface should be flat and perpendicular to the indentor of the test pieces should be
at least three times the diameter of the impression.
3) The distance between the center of two adjacent indentations or the center of any
indentation from the edge.
Experiment No. 9
AIM: To Conduct the hardness test on Brinell Hardness Tester.
OBJECT: To determine the hardness no. of mild steel, carbon steel, brass and aluminum
specimens.
APPARATUS USED: Brinell Hardness Tester, Brinell microscope, mild steel, carbon steel,
brass and aluminum specimens.
DIAGRAM:
BHN = Load Applied (kgf.)/ Spherical surface area indentation (in mm.)
2P
BHN
πD D D 2 d 2 (10.1)
Experiment No. 10
AIM: To conduct the testing of the spring on spring testing machine.
OBJECT: To determine the stiffness of the spring and modulus of rigidity of the spring wire
APPARATUS USED:
1) Spring Testing Machine
2) A spring
3) Vernier Calipers
4) Scale
5) Micrometer
DIAGRAM:
Mean k=
Dm
Spring Index
d
RESULT: The spring constant k of closely coiled helical spring is ………….. N/mm
PRECAUTIONS:
1) The dimension of spring should measure accurately.
2) Deflection obtained in spring should measure accurately