Stud
ent: Jagdishwar Kishor 264964237 Teacher: Tim Love
tt
1
MEM23061A Test Mechanical Engineering Materials
Lab
.
BEAM BENDING
Report
Answers
1. Use Solid Edge to calculate Ixx for each beam. Also determine the weight on CAD. Draw up the cross

section (either in part
mode or as a draft). While you are still in the
profile sketch (i.e. before going to a
solid) go to top menu:
Inspect > Area... > Click "Area Information" button in Ribbonbar > (click inside the
area you want to inspect) > Click on the green arrow in Ribbonbar. > You should see a table like this...
Ixx is the Second Moment of Area in bending with
a vertical load.
Sorry there is something wrong and
I
cannot figure it out !
Aluminium Channel
Command: MASSPROP
Select objects: 1 found
Select objects:

REGIONS

Ar
ea: 0.1837
Perimeter: 4.5203
Bounding box: X:

0.0037

0.8092
Stud
ent: Jagdishwar Kishor 264964237 Teacher: Tim Love
tt
2
Y: 0.0000

0.7632
Centroid: X: 0.3876
Y: 0.2965
Moments of inertia: X: 0.0270
Y: 0.0468
Product of inertia: XY: 0.0205
Radii of gyration: X: 0.3836
Y: 0.5049
Principal moments and X

Y directions about centroid:
I: 0.0108 along [0.9976

0.0691]
J: 0.01
93 along [0.0691 0.9976]
Aluminium Beam
Command: MASSPROP
Select objects: 1 found
Select objects:

REGIONS

Area: 0.2503
Perimeter: 4.5829
Bounding box: X:

0.0059

0.77
00
Y: 0.0000

0.8689
Centroid: X: 0.3790
Y: 0.4301
Moments of inertia: X: 0.0740
Y: 0.0447
Stud
ent: Jagdishwar Kishor 264964237 Teacher: Tim Love
tt
3
Product of inertia: XY: 0.0401
Radii of gyration: X: 0.5436
Y: 0.4225
Principal moments and X

Y directions about centroid:
I: 0.0087 along [0.0356

0.9994]
J: 0.0277 along [0.9994 0.0356]
Calculation for Aluminium Beam:
E1 & E2: Top and Bottom
Height = (hi

h2) / 2 =
(22.1

19.1) = 1.5mm
d1 = 19.1/2+(1.5/2)=10.3mm
Ic1=bd^3/12=18*1.5^3/12=5.0625mm4
I1=Ic1+Ad^2
= 5.0625+(18.1*1.5)*(10.3^2)=2869.4925mm4
E2:
Ic2=bh^3/12=1.5*19.1^3/12=870.983875mm4
Total I=I1+I2+I3
= 2.69.4925+2869.4925=870.983875=6609.968875mm4
20120809 Test results:
Specimen
I Second
Moment
of
Area (mm4)
Modulus of Elasticity
E
Maximum Stress f( Mpa)
Aluminium Channel
2 kg + 1 lb Hook
5kg + 1 lb Hook
7 kg + 1 lb Hook
Aluminium Channel
2 kg + 1 lb Hook
5kg + 1
lb Hook
7 kg + 1 lb Hook
Tas Oak Timber
100 g Hook
154.1
67665.77494
7.042383193
300 g Hook
154.1
102545.0404
21.12714958
500 g Hook
154.1
109788.8401
35.21191596
Steel Flat Bar
Stud
ent: Jagdishwar Kishor 264964237 Teacher: Tim Love
tt
4
1 lb hook only
260.42
183935.1456
10.59466439
500 g + Hook
260.42
195682.5346
22.36651371
1 kg + Hook
260.42
191251.3335
34.13836303
Steel Square Bar
2 kg + 1 lb Hook
894.73
174339.9121
34.18226867
5 kg + 1 lb Hook
894.73
176330.554
76.03810786
6 kg + 1 lb Hook
894.73
181666.4088
89.99005
426
Aluminium Beam
5 kg + 1 lb Hook
6609.97
67403.86114
18.19904251
8 kg + 1 lb Hook
6609.97
65316.81498
28.21686407
10 kg + 1 lb Hook
6609.97
68022.24518
34.89541178
Tas Oak Timber
200 g
977.96
20898.09399
2.106527874
400 g
977.96
2
0876.79114
4.208761095
600 g
977.96
20898.09399
6.319583623
2. Write a short
report on the beam bending results. Each beam must have at least 3 weights. Make sure the
deflection does not exceed the travel of the dial indicator (if so, use a lighter we
ight).
Testing:
In our test, the specimen are supported at both ends in a
simply supported
beam configuration. Th
e
supports are placed on the rig or pivots
.
Small weights (
masses
) are used to load the beams and
deflections measured with a vernier calipe
r and recorded.
Stud
ent: Jagdishwar Kishor 264964237 Teacher: Tim Love
tt
5
Specimen
Start
5
kg + Hook
2.2
kg
8 kg + Hook 2.2
kg
10
kg + Hook
2.2
kg
Aluminium Beam
18.0
0
mm wide x
50.50 mm
48.00 mm
46.50 mm
45.75 mm
Stud
ent: Jagdishwar Kishor 264964237 Teacher: Tim Love
tt
6
22.10 mm height x
1.50 mm cross

section
Specimen
Start
100 g + Hook 100g
300 g + Hook 100g
5
00 g + Hook 100g
Tas Oak Timber
19.80 mm wide x
8.40 mm height
37.00 mm
35.00 mm
33.00 mm
31.00 mm
3. Using the equations above, calculate the value of E. Compare these values to the values obtained from
the
internet. E.g. Matweb. Show the working for
1 example calculation, but only give the rest of the answers in
a table. Use Excel to do your calculations.
Modulus of Elasticity
E =
W * L
3
/ (48 * z * I)
= 1.962*1000^3 / (48* 2*977.96)
=
20898.09399
Please refer to table above in Q1
.:
4. D
etermine the maximum stress
for each mass (load) added to the beams.
Please refer to table above in Q1.:
5. Discuss any sources of error in the experiment

esp.
measurements

and how they might affect the
results. Specify an overall error for your calc
ulation of E.
During this procedure, a few
measurement uncertainties did
affect the results. First, the
dimensions pertaining to the spe
cimen were given in
millimetres
.
It was
estimated to be an error of
±0.05
mm. Also, the calculated
weight (newtons) had t
o be converted to mass for measurement. This
uncertainty in conversion
was estimated t
o be 0.5%. The weight of the hook
was to be determined and
subtracted from this
value to find the load for each stress level. The error in calculating the
weight was
assu
med to be 10g, although the
tec
h
nique
used to find it (hanging increasing counter
weights
) was highly subjective and could have resulted in
significantly more error, which
was impossible to
determine.
Other errors did
occur reading the
vernier calipers
wh
en calibrating the specimen in the machine.
Human error and w
ell as the accuracy of the caliper
itself could cause error in loading
and measuring
the
part.
Since the equation to find the applied stress has a set value for the distance between the loaded
en
ds of the specimen
, improperly loaded specimens would be incorrect as well. The
mass applied to the specimen depends on the certainty of the label
l
ed weights. The specimens
varied
in weight and dimensions causing variance in the results.
Comments 0
Log in to post a comment