Page 198 - Bridge and Highway Structure Rehabilitation and Repair

CHAPTER 4 AN ANALYTICAL APPROACH TO FRACTURE AND FAILURE 173

f 3 M/s f 3 My /s f 3 Mp /z
b
y
y
f b f y f y
d
/2

Yield
Stress
Figure 4.15 Elastic, elasto-plastic and plastic stages at location of peak moment in rectangular beam.

Circular 1.7
Rectangle 1.5

Wide flange weak axis 1.5
Round tube 1.27
Rectangular tube (width 3 depth/2) 1.20
Wide flange strong axis 1.14

4.15 PLASTIC BEHAVIOR OF STEEL NON-COMPOSITE SECTION
4.15.1 Plastic Moment of a Non-Composite Section
Part elevation cross section plastic stress distribution:
In Figure 4.16, the sum of all horizontal forces 3 0
Fc 4 Fwc 3 Fwt 4 Ft

b f f yf

t w
d
h f yw

b b

Figure 4.16 Plastic forces acting on non-composite section.