ness 1) The plates are parallel with a clear distance D between them
(D > 1) The axis of bending is parallel to the plates.
Plates (150 mm x 12 mm) are welded to the flanges of an I-beam
(S = 1800 cm', overall depth = 4674 mm). Find the plastic moment of
the combined section, assuming a yield stress of 275 N/mm?
2.2.
Show that the plastic moduli for bending about the y- and z-axes of the
channel section in figure 2.23 are
S= SD?,
for bending about the y-axis
S= 1.75D71
for bending about the z-axis
2.3. Find the plastic moment of the section shown in figure 2.24. Assume the
yield stress is 350 N/mm?.
2.4. Find the plastic moments of
(a)
a solid circular section, diameter D, bending about a diameter;
Plastic Bending
Dy:
Figure 2.23
30
90
220
Figure 2.24
(b)
a thin-walled square section, side length d, thickness + (d> 1),
bending about an axis parallel to two sides;
(C)
(d)
the same section as in (b), bending about a diagonal;
a thin-walled equilateral triangle section, side length a, thickness
1 (a > 1), bending about an axis parallel to one side.
2.5.
Derive the expressions in equations 2.17 and 2.19 for the reduced plastic
moment, due to an axial force, of the I-beam in figure 2.10. Derive also
the corresponding expressions for bending about the z-axis
The beam 533 x 210 UB 122 has the properties:
D= 544.6 mm
B= 211.9 mm
1= 12.8 mm
T= 21.3 mm
38
Plastic Methods for Steel and Concrete Structures
A= 155.8 cm?
dy = 265 N/mm?
S= 3202 cm' for bending about the y-axis
S= 500.6 cm for bending about the z-axis
Find the reduced plastic moments when it carries axial forces of 1150 kN
and 2300 kN.
- 2 1 Calculate The Plastic Moment Of A Pair Of Identical Plates Width B Thick Ness 1 The Plates Are Parallel With A 1 (24.04 KiB) Viewed 32 times