enge1001 deflection of beams objective to verify the relationship betw

Question

ENGE1001 - Deflection of Beams
Objective:
To verify the relationship between load and deflection for a simply supported beam with
a single concentrated central load.
(Note: You may find other objectives after doing the experiment)
Apparatus:
Knife edge supports, dial gauge, weights and weight carrier.
Method:
•
• 1 Mild steel bar
• 1 Brass bar
25.4mm x 4.76mm
25.4mm x 6.35mm
Set up each beam in turn centrally on knife edge supports near the ends of the beam.
Locate the dial gauge centrally between supports and set to zero.
•
Apply loads in 200 gram increments to 1600 grams, noting deflections.
• Repeat while removing loads.
NOTE: The beam should be vibrated gently before each reading is taken to ensure that it
is properly settled on the knife edges. You may take a picture of the setup for your report./nCalculations:
The equation for the deflection at the centre of the beam, for a simply supported beam
with a single concentrated central load, is as follows:
Given:
Where
y
L
I
E for Mild Steel Beam:
E for Brass Beam:
Deflection (m)
W - Load (N)
Length (m)
E-Young's Modulus (N/m²)
Second moment of Area [about the Neutral Axis] (m¹)
b
b (breadth of the beam)
d (depth of the beam)
Units
y =
m
WL³
48EI
Complete the following table by showing the relevant calculations:
m
207GPa
110GPa
Cross section of the beam
Mild Steel
Brass/nGraph:
Ploty / Deflection (mm) (Y-axis) vs. W / Load (N) (X-axis) for both beams in a single
graph.
Discussion:
• Is the deflection vs. load graph a straight line? Support your answer by (i) observing the
graph and (ii) with the help of the deflection equation.
• State three main errors that may have occurred in your assumptions and in the
measurements.
• Discuss why the brass beam is deflected less compared to the mild steel beam for the
same load in this experiment; support this with evidence.
Conclusion:
• Summarise key points/findings of the experiment
• Very briefly explains where this knowledge could be applied
Additional note:
• No more than 5 pages of report in total should be returned as additional pages will not
be marked. This does not include the cover page.
• Fonts should not be smaller than size 11.
The key for a good report is 5Cs - Clear, Concise, Complete, technically Correct and
Critical analysis
• Show your calculations to prove that you know how to do them
• Make the report looks nice and well-formatted - reuse the tables from the lab sheet
but feel free to make adjustments
Use diagrams or photos where appropriate (with figure number and description)