PASCO ME-9891 Flexible I-beam - Manual (Page 8)

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F l e x i b l e I - b e a m E x p e r i m e n t : T h r e e - p o i n t B e n d i n g
8
Analysis
1. For the data taken with the beam in the upright orientation, make a graph of y
max
(the measured deflection in the center of the beam) versus F (the force applied by
the force sensor).
2. Apply a linear fit to the data. The relationship between y
max
and F is given by
Therefore, the slope of the best-fit line is .
3. Measure L, the distance between the supports.
4. Use the slope of the best-fit line and L to find EI, the beam’s flexural rigidity.
5. Repeat the analysis for the beam in the side orientation.
Questions
1. In which orientation did the beam have greater flexural rigidity? How much
greater was it?
2. Was the prediction that you made at the beginning of this experiment accurate?
Further Study
Repeat the experiment with a cantilevered beam (Figure 2b). Does the maximum
deflection for a given force change? Does the flexural rigidity change?
y
max
F
L 3
48 EI
------------ – =
L 3 48EI
( ) ⁄
–