MAE 156A
Homework 5 Solution
Problem 5.5 (20 pts)
For the simply supported beam determine the bending stress at points D and E. The cross section is a
0.15 0.15 0.02m angle section.
Figure 1: Figure P5.5
First of all compute the bending moment at midspan
MAE 156A
Homework 7 Solution
Problem 4.14 (20 pts)
The most critical point in the rod is A where we have axial tension due to P, axial tension due to R and
torsion due to R. The stress state at A is:
50R
P
24R
8R
+ MI r TJr
a a
2 + 5r 3
5r 3
= r
= TAr
8
MAE 156A
Homework 6 Solution
Problem 6.35 (15 pts)
For closed thin-walled sections use Bredts formulas (Eqs 6.22 and 6.23):
I
1
T
=
ds
=
2At
2AG
For the hexagon we have the following area and perimeter:
3 3a2
A=
s = 6a
2
Substituting:
T 3
=
9a2 t
=
2T
9G
For problem 5, you are given the traction t and the normal force. The first goal is to solve for x,
y and xy before performing any stress transformation using the eqn below:
First solve for y and xy on the top plane:
[nx , ny]
For this case, fx = 0, fy =
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University of California, Los Angeles
Mechanical and Aerospace Engineering Department
School of Engineering and Applied Science
MAE 156A, Advanced Strength of Materials
Fall 2016
Final Solution
Instructor: Giacomo Po
1
Problem 1 (elasticity, 10 pts). A re