Introduction to Continuum Mechanics
Instructor: Peter Taylor; TA Shama Sharma
Lab #3: Beam Bending: March 8 and 15, 2011 14:30-17:30 @ PSE 133
Purpose: The aim of this lab is to determine Young’s modulus for steel and aluminum bars by
measuring the amount of deflection beams of known cross section undergo under a specified
load, and to plot the comparisons between theoretical and observed values of displacement at
positions along the beam.
Case 1: Beam is supported at both ends and single load at the centre
1. First find the length (l) of the beam using metre scale. Then
2. Measure width (w) and thickness (h) of the beams using Vernier Callipers.
3. Find moment of Inertia of the beam cross section using Formula
4. Complete the observations for Case1 using two masses for each beam.
Material Mass Deflection Deflection Deflection Deflection Deflection Young
at centre, at position at position at position at position Modulus for
(kg) x0 (mm) x1 (mm) x2 (mm) x3 (mm) x4 (mm) position x0
Steel 0 kg
I = (m )
Aluminum 0 kg
I = (m )
5. Use your observations for maximun deflection(y) at the centre to find Young’s modulus (E)
for both of the beams using the formula, ymax