CEE-181 Design of Steel Structures
Autumn, 2015-2016
Catalogue Description: Concepts of design of steel structures with a load and resistance factor (LRFD)
design approach; types of loading; structural systems; design and behavior of tension members,
comp
120
Design of Beam-Column Members Summary
M1
M2
Pu
Load Effect
Basic Principle:
1.0
Resistance
M uy
Pu
Pu
8 M ux
For
0.2 ;
c Pn 9 b M nx b M ny
c Pn
Pu
1
(AISC Eq. H1.1a)
For
M ux
M uy
Pu
1 Pu
0.2 ;
c Pn
2 c Pn b M nx b M ny
1
(AISC Eq. H1.1b)
Mo
101
Design of Flexural Members Summary
Objective: Design Strength
Mu
bM n
Moment capacity:
b
Mn
b
Mp
b
Q
i
i
(Required Strength) where
b
0.9
Fy Z x
Local buckling of thin elements (compactness of section)
b
b
Mn
b
Mp
b
Mr
M
(0.7 Fy S x )
(Flange Local
Buc
11
Loads
Gravity Loads: dead loads, live loads, snow loads,
Load Path: A gravity load goes from its point of application on the structure to the foundation.
As an example, the load applied on a slab will distribute to the beams, then to the girders,
colu
28
Design of Tension Members Summary
Objective: To provide sufficient area (member) such that
t Pn iQi ( Pu )
Basic Design Criteria:
Yielding along member: t 0.9 ; Pn Fy Ag
Fracture at connection: t 0.75 ; Pn Fu Ae
Effective Net Area:
1
Calculation of Net
79
Design of Compression Members Summary
Objective: Design Strength c Pn c Fcr Ag Pu i Qi
(Required Strength)
Compressive Strength: The critical stress value Fcr is given as
If
KL
E
4.71
,
r
Fy
Fcr 0.658 Fe
KL
4.71
If
r
Fy
where Fe
Fy
E
,
Fy
Fcr
ET
1
Introduction to Building Structures and Basic Structural Elements
Multistory (Office) Buildings
Structural Elements: beams, columns, connections, floor systems, bracings,
(Ref: Aghayere and Vigil, Structural Steel Design A Practice Oriented Approach, P