All experiments of mechanics of solid with data.

1. UNIVERSITY OF ENGINEERING AND TECHNOLOGY PESHAWAR
MECHANICS OF SOLID REPORT BY GROUP A1
LABREPORTOFMECHANICSOF
SOLIDS
CE-119L LAB REPORT

2. 1
MECHANICS OFSOLIDS CE-119LLAB REPORT
1. TO FIND FORCES IN VARIOUS PARTS OF THE ROOF
TRUSS
OBJECTIVE:
 To observe how force (applied load) is distributed over the members of a Truss.
CONCEPTUAL BACKGROUND:
LAW OF TRIANGLE:
When three concurrent and co-planar forces are in equilibrium, then they can be represented by the three
sides of a triangle. By taking joints one by one we can draw the triangle of forces and thus find out the two
unknown forces.
APPARATUS:
 RoofTruss
 Weights
 Measuring tape
 Spring balance
RoofTruss:
“A type of structure formed by members in triangular form ad have pin connected
joints is called truss”. Loads can be applied only at its joints.

3. 2
TRIANGLE LAW
“If two forces acting at a point are represented in magnitude and direction by two
adjacent sides of a triangle taken in order that the closing side of triangle taken in the
reverse order represents the resultant of the forces in magnitude and direction is called
triangle law.
PROCEDURE:
 First of all set a simple truss on the table .
 Apply some load at C.
 The legs of the truss will extend in such a way that two members of the truss will be in
compressionwhile the third member will be in tension.
 When the system acquires equilibrium, measure the lengths of all three members of
the truss understudy.
 Constructa triangle with these measurements and indicate reactions at respective
positions with the help compass. (FBD)
 From this FBD, draw a load diagram in such a way that each side of load diagram is
parallel to the respective sides of FBD.
 Measure the side of the triangle obtained from the load diagram and convert them into
forces through calculations. This will give the reactions as well as forces distributed
among the members of truss understudy.
OBSERVATIONS AND CALCULATIONS:
S.no Applied
Load
AB BC AC Observed
Tension
C1 C2 T AY RBx RBy
1. 6lb 34.2” 28” 23.5” 4lb 4.5lb 3.6lb 2.8lb 3.5Lb 0lb 2.4lb
2. 4lb 34” 28” 23.5” 2lb 3lb 2.5lb 1.8lb 2.4lb 0lb 1.6lb
3. 10lb 34.5” 28.5” 23.5” 5lb 7.3lb 6.7lb 5lb 5.5lb 0lb 4.5lb
SNO. ANAYLITICAL METHOD
C1 C2 T AY
BY
1 4.43” 3.47” 2.5” 3.6” 2.33”
2 2.94” 2.26” 1.6” 2.4” 1.55”
3 7.4” 6” 4.26” 6.9” 3.9”

4. 3

5. 4
2. TO EXPERIMENTALLY FIND THE FORCES IN
VARIOUS PARTS OF WALL CRANE
OBJECTIVE:
 To observe how force (applied load) is distributed over the members of a Wall
Crane.
CONCEPTUAL BACKGROUND:
LAW OF POLYGON:
. If a number of forces acting simultaneously on a particle be represented in
magnitude and direction by the sides of a polygon taken in order, their resultant may be
represented in magnitude and direction by the closing side of the polygon taken in
oppositeorder.
APPARATUS:
 Wall Crane
 Weights
 Measuring tape
 Spring balance
Wall Crane
Weights

6. 5
Wall Crane:
In engineering, a crane is a structure that "have a horizontal arm (with or without a
trolley); supported from a sidewall or line of columns of a building; has a maximum
swing of a half circle
Used mostly in industrial premises and on military vehicles, the jib may swing
through an arc, giving additional lateral movement.
PROCEDURE:
 Measure length of OA, OB, AB.
 Apply some load at C.
 OA and OC will be in tension while OB will be in compression.
 Tension in OC will be equal to applied weight.
 When the system acquires equilibrium, measure the length of all members of wall
crane.
 Constructfree bodydiagram with these measurements.
 From FBD draw load diagram in such a way that each sides of load diagram is parallel
to FBD while the length of T2 should be the same as that in FBD. And also select
suitable scale for weight i.e 1lb=1”.
 Now measure sides of polygon obtained in load diagram and convert them into force.
OBSERVATIONS AND CALCULATIONS:
S.no Applied
Load
T1 T2 C AC BC OA OB T1 C T2
1. 4lb 2.4lb 4lb 6lb 8.8” 11” 21.8” 19.8” 1.8lb 5.9lb 4lb
2. 6lb 3.9lb 6lb 9lb 8.8” 11” 22.5” 20.1” 3.4lb 8.9lb 6lb
3. 3lb 1.9lb 3lb 4lb 8.8” 11” 21.5” 20” 1.8lb 4.2lb 3lb

7. 6

8. 7
3. VERIFY THE LINK POLYGON METHOD FOR
COPLANAR FORCES
OBJECTIVE:
 To verify whether the system of closed polygon is in equilibrium or not.
 To find unknown forces in a given system.
CONCEPTUAL BACKGROUND:
LINK POLYGON METHOD:
Link polygon method is a graphical solution to determine the equilibrium of system
of coplanar forces. Ifthe system is in the equilibrium, the vectors drawn parallel to external
forces will make a closed polygon. Line drawn to link will meet in a point showing triangle
of forces for each joint which is also in equilibrium.
APPARATUS:
 A3 sheet
 Weights
 Ruler
 Mirror
 Thumb pins
 Pencil

9. 8
PROCEDURE:
 First of all we have to suspend loads from threads and establish the equilibrium .
 First of all pin up the A3 sheet on the board (on which the mass pulley system is
arranged).
 The polygon is in tension because the cables which make the polygon are under the
action of tensile force (tension). Each one of the pulley as well as weight suspended at
point D.
 There are five unknown forces in the polygon i.e. T1, T2, T3, T4 and T5. While the
upper two weights W1 and W5 are 1lbs. and the lower two weights W2, W3 and W4 are
0.5Ibs.
 Take mirror place it behind the cable under tension T1and mark the point where image
of the cable and actual cable coincide. Mark two points on both sides of the mirror
with the help of pencil.
 In the same way, mark points for T2, T3, T4 and T5 as well as for W1, W2, W3, W4 and
W5 respectively.

10. 9
 Detach the sheet from board and start connecting the points with the help of ruler and
pencil. Make sure figure should be similar to the polygon.
 Draw the load diagram, starting from the known forces i.e. W1, W2, W3, W5 and then
the unknown forces T1, T2, T3, and T4 in such a way that the representative lines are
parallel to all these force respectively.
 Measure the length of T1, T2, T3, and T4 in cm from ruler and reconvert into lbs.
OBSERVATIONS AND CALCULATIONS:
S.no External Force
(lbs.)
Tension in cables
T(lbs.)
Reading:1
(lbs.)
1. W1=0.5 T1 0.37
2. W2=0.5 T2 0.59
3. W3=1 T3 0.86
4. W4=1 T4 0.62
5. W5=0.5 T5 0.39

11. 10
4.TO VERIFY PRINCIPLE OF MOMENT ON DISC
APPARATUS.
OBJECTIVE:
To verify the principle of moments which states that if a number of coplanar forces acting
on a body, keep it in equilibrium and their moment are taken about any point in their
plane, the sum of the clockwise moments, is equal to sum of anticlockwise moment. the
pulleys and the disc should rotate freely.
CONCEPTUAL BACKGROUND:
PRINCIPLE OF MOMENT:
The principle of moment state that, when a system is in equilibrium, the sum of all anti -clock moment is
equal to the sum of all anti-clockwise moment.
APPARATUS
 Disc apparatus
 Weights
 Calculator
D
PROCEDURE:
 First set up all the apparatus before starting the experiment.
 When no weight is attached note that the hooks should be in equilibrium. If not, we
have to remove the error by balancing all the hooks.
 Labeled all the hooks.

12. 11
 Now put the weights in each hooks in such a way to keep all the hooks in
equilibrium.
 Measure the length between the hooks.
 Keep on applying the weights and measure the length between the hooks.
Note all the readings.
 Calculate the moment produced bythe weights on left side of center point, and also
the moment produced by weights on right side of center point.
 Left side moment should be equal to right side moment (clock-wise moment=anti
clock wise moment) to verify principle of moment.
OBESRVATIONAND CALCULATION:
S.NO
W1
(lb)
W2
(lb)
W3
(lb)
W4
(lb)
L1
(in)
L2
(in)
L3
(in)
L4
(in)
Clock-
wise
moment
Anti-
clock
wise
moment
1 1.5 0.5 1.5 1 4.5 2 2 5 7.75 8
2 1 2 1 1.5 4.8 2 2 4.5 8.8 8.75
3 1 1 1 1 5 2 2 5 7 7

13. 12
5. TO VERIFY LAW OF PARALLELOGRAM OF FORCE.
OBJECTIVE:
To experimentally verify law of parallelogram of forces using force table.
CONCEPTUAL BACKGROUND:
LAW OF PARALLELOGRAM OF FORCES:
This law states, “If the adjacent sides of a parallelogram represent two vectors,
then the resultant of these vectors is given by diagonal of the parallelogram.
Concurrent forces are forces that pass through the same point. Resultant is a single
force that can replace the effect of a number of forces. Equilibrant is a force that is
exactly opposite to a resultant. Equilibrant and resultant have equal
magnitudes but oppositedirections.
APPARATUS:
 Weights
 Gravesend’s Apparatus (pulley-cable arrangement)
 A4 paper
 Pencil
 Setsquares
 Thumb pins
 Mirror

14. 13
Gravesands apparatus
PROCEDURE:
 First of all we will apply loads passing through the pulley of wooden board .Once
the system is in static equilibrium, with the help of mirror, mark the points where
images of the cables, under tension due to applied loads, in the mirror and actual
cables coincide respectively.
 Join all these points according to the system of cables on Gravesend’s apparatus.
 Now, draw load diagram according to a suitable scale in such a way that each line
is parallel to its respective force.
 Once the load diagram is constructed, apply law of parallelogram of forces by
drawing parallel lines to the line representing T1 and T2. You will get a
parallelogram.
 Diagonal of this parallelogram represents resultant of T1 and T2 which should be
equal to T3 which tension due to W3.
 Repeat the experiment with different weights applied in place of W1, W2, W3.

15. 14
OBSERVATIONAND CALCULATIONS:
W1 (lbs) W2 (lbs) W3 (lbs) R (lbs)
2 2 2 2
1 1.5 2.5 2.5
Diagram

16. 15
6. MEASUREMENT OF REACTION AT SUPPORT IN
STATICALLY DETERMINATE: SIMPLY SUPPORTED
BEAM
OBJECTIVE:
To find out reactions at support of simply in statically determinate simply supported
beam by using equilibrium conditions.
CONCEPTUALBACKGROUND:
EQUILIBRIUM OF VERTICAL FORCES;
Sum of all upward and downward forces should be equal to zero.
EQUILIBRIUM/PRINCIPLE OF MOMENTS:
The principle of moment state that, when a system is in equilibrium, the sum of all anti -
clock moment is equal to the sum of all anti-clockwise moment.
APPARATUS:
 Weights
 Spring Balance
 Simply Supported Beam
 Bubble level.
Simply Supported Beam

17. 16
PROCEDURE:
 To check whether the simply supported beam is balance we use Bubble tube.
 First measure the self weight of the beam which is 5.84lb.
 As beam is supported bytwo unknown reactions RA and RB place two different
weights on it.
 After the beam comes in equilibrium state measure the magnitude of the weights
W1 and W2 by the help of spring balance
 Measure the distances of weights W, W1, W2.
 The distances of weights are OA, OB, OC and OD on the beam at point O.
 Calculate the supportreactions RA and RB (by using the method of Equilibrium of
vertical forces and Principle of Moments)
OBSERVATIONAND CALCULATIONS:
S.no W1(Ibs) W2(Ibs) RA(Ibs) RB(Ibs) OA OB OC OD RA(Ibs) RB(Ibs)
1. 0.36 0.36 3.21 3.34 0 41 27 7 2.49 3.21
2. 0.61 0.61 3.4 3.5 0 41 5 34 2.28 3.58
3. 0.75 o.75 3.6 3.8 0 40 30 16 3.56 3.78

18. 17
7. TO FIND THE YIELD/TENSILE STRENGTH OF THE
STEEL BAR
OBJECTIVE:
This test is performed at which the steel bar yields when load is
continuously increased.
APPARATUS:
 Steel rod for test.
 Standard ruler.
 UTM (universal testing machine).
 Vernier caliper or screw gauge
UTM: This is a machine which is originally made to perform thr compressive, Tension,
Shear and bend for different materials. It consists of mainly two units
1) LOAD MEASURING MACHINE: It is the unit in which we measure the
applied load.
2) STRAINING UNIT: In this unit the steel bar is placed and deformation is
measured for strain.