Strength of Materials II (MENG 3024): In-course 1 (18th October 2018)
ANSWER ALL QUESTIONS
Write in pen only.
Question 1
1a. A simply supported beam 6 m long carries a uniformly distributed load of intensity 2000 N/m
along its entire length and acts vertically downward. The cross-sectional area for the beam is the
angle section shown in Fig. 1. The uniformly distributed load acts normal to the 100 mm side
directly through the centroid ‘C’.
Determine the following properties of cross sectional area:
i.
The second moments of area (Ix) and (Iy) about the centroidal axes x and y.
[2]
ii.
The product of inertia (Ixy) about the centroidal axes.
[1]
iii.
The principal second moments of area of the section clearly stating the location of the
principal axes relative to either the centroidal x or y axes.
[3]
iv.
The maximum tensile and maximum compressive bending stresses in the beam due to the
uniformly distributed load.
[4]
v.
The location of the neutral axis of bending.
[1]
Figure 1
1/2
1b. The Aluminum channel shown in Figure 2 is used as a cantilever of span length 100 cm. At
different instances a single load P=100 N acts through the centroid C at the free end of the beam.
The direction of load P for each load case is shown by an individual solid arrow acting through the
centroid C in Figure 2. In the figure below the x,y axes are the centroidal axes. What are the
maximum (δmax) and minimum (δmin) expected deflections at the free end?
[4]
The Young’s modulus E for Aluminum is
0.8 107
N/cm2.
Figure 2
2/2