Civil Engineering Reference
In-Depth Information
8 2 . 7 6
61. 54
200
1 0 0
0
0
= =0
L
L
= =0
1 2
20
6
mL
/4
150
m
S
C
500
6
10
L
/2
L
/4
L
/4
6
20
(a) Box section
(b) Channel
section
(c)
Statically indeterminate
beam
Figure 10.38
Examples 8-13.
10.10 Unworked examples
10.10.1 Example 8 - uniform torsion of a box section
Determine the torsion section constant
I
t
for the box section shown in
Figure 10.38a, and find the maximum elastic shear stress caused by a uniform
torque of 10 kNm.
10.10.2 Example9-warping torsion section constant of a
channel section
Determine the warping torsion section constant
I
w
for the channel section shown
in Figure 10.38b.
10.10.3 Example 10 - approximation for the maximum
twist rotation
The steel beam shown in Figure 10.38c is 5 m long, has the cross-section shown
in Figure 10.38b and a torque per unit length of
m
=
1000 Nm/m. Determine
approximate values of the maximum angle of twist rotation by assuming
(a) that the beam is in uniform torsion (
EI
w
≡
0), or
(b) that the beam is in warping torsion (
GI
t
≡
0), or
(c) the approximation of equation 10.56.
10.10.4 Example 11 - accurate twist rotation
If the steel beam shown in Figure 10.26 is 5 m long and has the cross-section
shown in Figure 10.38b, determine an accurate value for the maximum angle of
twist rotation.
Search WWH ::
Custom Search