propped cantilever beam discussion report

1. DISCUSSION
Based on the experiment propped cantilever beam that have been done, data
was obtained in order to calculate the reactions and fixed end moment with the given point load
and distributed load which is 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, 7.5, and 8.5 N respectively. Each of the
load produced its own reading which differ from each other. The calculation was done by using
Superposition Method which is one of the method that are used in structural analysis to obtain
the value required. This method was required in order to draw the Shear Force Diagram and
Bending Moment Diagram of the beam use. After the results of the calculation was produce, a
checking percentage of an error between the experimental and theoretical must be done so that
comparison can be make. The formula of checking this percentage of error is,
% Error = The difference in reaction X 100%
Reaction theory
While the formula for checking the fixed end moment percentage error is,
% Error = The difference in the fixed end moment X 100%
Fixed end moment theory
From the data that were obtain from the experiment which is been tabulated in
table, its shows that the value of theory and error produced was differ from each other. This
prove that the experiment being conducted was not as expected as it should be. Besides that, the
calculation done maybe have a little bit error because of the calculation was being done manually
and not by computer. The cause of this error also maybe come from the equipment itself which
may be too long not being maintained its part. Therefore, the error occur must be overcome and
fixed in order to obtain a solid and clear data between theoretical and experimental and also fixed
end moment error.

2. Each point load used was being calculated using Superposition Method to
obtain the required value. For point load 1.5N, the theoretical value was 0.585 while the percent
error was 0.85% for reaction 1. For reaction 2, the theoretical value was 0.915 while it’s percent
error were 93.44%. The fixed end moment error was 22.01% and its theoretical value is 0.0795
which can be seen that three of them except for reaction 1 were differ greatly from each other.
For point load 2.5N, the theoretical value is 0.972 while the percent error is
0.926% which is can be accepted because the difference between them are not too great in
reaction 1. For reaction 2, the theoretical value is 1.528 and the percent error is 98.45% while the
fixed end moment theoretical value were 0.133 and the percentage error was 25.56% which this
value is greater differ from each other.
For point load 3.5N, the theoretical value is 1.33 and the percentage error are
3.26% which not too far from theory for reaction 1. Theoretical value for reaction 2 is 2.17 while
its percentage error were 99.08% and this proved that data from the experiment could not be rely
completely. The fixed end moment for the theoretical value is 0.916 and the percent error was
21.43%.
For point load 4.5N, the theoretical value for reaction 1 were 1.78 and its
percentage error was -6.18%. This negative value were obtain from the experiment which may
affect the theory value. In reaction 2, the theoretical value were 2.72 and its percentage error was
101.84% which is bigger than its supposed to. The fixed end moment theoretical value were gain
was 0.231 and the percentage error were 30.74% respectively.
For point load 5.5N, the theoretical value and percentage error for reaction 1
were 2.11 and 7.11% respectively. They are still have great differences if being compared. For
reaction 2, the theoretical value and the percentage error gain was 3.39 and 90.86 respectively
while the fixed end moment theoretical value and its percentage error was 0.302 and 88 each.
For point load 6.5N, the theoretical value is 2.56 while the percentage error
are -4.18% on reaction 1. This value gained were not satisfied because of the differences in the
theory and experimental value was too great. For reaction 2, 3.94 was its theoretical value while
the percentage error is 91.32% and this value still not obey the theory provided. The fixed end
moment theory value was 0.337 and the error percentage is as much as 23.02%.

3. For point load 7.5N, the theoretical value in reaction 1 was 2.89 and the
percentage error is -1.73. This stills show that the data not getting together as it should be. While
in reaction 2, the theoretical value is 4.61 and its percentage error were 87.20% which is differ
greater than theoretical value. The fixed end moment theoretical value is 0.41 and the percentage
error were 14.63 respectively.
For point load 8.5N, the theoretical value for reaction 1 were 3.33 and -
90.39% was its percentage error. For reaction 2, the value for its theoretical was 5.17 and the
percentage error are -80.46% each. While the fixed end moment value of theoretical were 0.45
and the value for its percentage error was 21.11%.
The data collected from the experiment are going to be used in determining
the reactions of propped cantilever beam subjected to point load and distributed load. Even
though the data does not being comparable between theory and experimental and fixed end
moment value were differ from the expected value, its still can be used to calculate the reactions
and its fixed end moment. The experiment was successfully conducted and the report of the
experiment were presented gratefully.