SC 411: DESIGN OF STEEL
STRUCTURES
8 UNITS
Course Objectives
1.
To introduce to students the theory and application of analysis
and design of steel structures.
2.
To develop students with an understanding of the behavior and
design of structural steel members and systems.
3.
To prepare students for the effective use of the latest industry
standards, codes of practice and design aids in the design of
structural steel members.
Course outline
1
1.1
1.2
1.3
Concepts of Structural Steelwork
Structural steel
The importance of steel building materials
Structural steel sections
2
2.1
2.2
2.3
Design philosophy for Structural Steelwork
Requirements for structural steel work
Ultimate limit state theory
Serviceability limit state theory
Course outline
3
3.1
3.2
3.3
3.4
3.5
3.6
Design of Structural Steel Elements
Tension members,
Compression members,
Design of flexural members,
Lateral torsional buckling of beams,
Members subjected to combined axial and flexural loads
Bases
4
Design of Connections
4.1 Welded connections
4.2 Bolted connections
Learning Outcomes
Upon completion of this course, students should be able to:
1.
recognize the design philosophy of steel structures and have concept
on limit state design understand the behavior of steel structures, in
particular the various forms of failure for members and connections,
under tension, compression, bending and combined actions
2.
understand the behavior of steel structures, in particular the various
forms of failure for members and connections under tension,
compression, bending and combined actions
3.
apply the principles, procedures and current code requirements to the
analysis and design of steel tension members, beams, columns,
beam- columns, bases and connections
Mode of Assessment
1.
Continuous assessment (CA):
1.1
Closed book mid semester test (at week 7 -9) …….… 20%
1.2
Group project (to be submitted at week 13 – 14) ……. 20%
Total (1.1 +1.2) ………………...………………………….. 40%
2.
End of Semester (UE) closed book exam ..……..……. 60%
Total maximum course score (CA + UE) …………………..…100%
Lecture 1.1
1.1.1 Concepts of Structural Steelwork
What are Steel Structures?
➢A structure which is made from organised combination of structuralSTEEL
members designed to carry loads and provide adequate rigidity
➢Steel structures involve a sub-structure or members in a building made
from structural steel.
Some famous steel structures
WALT DISNEYCONCERTHALL,US
TYNEBRIDGE,UK
HOWRAHBRIDGE,INDIA
Advantages of using Steel in Structures
➢ High strength
➢ The high ratio of strength to weight (the strength per unit weight)
➢ Excellent ductility and seismic resistance
➢ Withstand extensive deformation without failure even under high
tensile stress.
➢ Elasticity, uniformity of material
➢ Predictability of properties, close to design assumption
➢ Ease of fabrication and speed of erection
Most important
Steel structures facilitate ease of fabrication and faster
erection of structure. Bolts and welding employed for
joining .
Disadvantages of using steel in a structure
• Susceptibility to corrosion
• Maintenance costs / thin-walled structure
• Loss of strength at elevatedtemperature
• Fireproofing costs
• Susceptibility to buckling
• Fatigue and brittle fracture
Bucling phenomenon
Where & when use steel structures?
1. Long-span structures
2. Multi-storey & high-rise buildings
3. Buildings of heavy duty plants
4. Tower & mast structures
5. Portal frames
6. Bridges
7. Infrastructures
1.1.2 Structural Steel Elements
Steel buildings are composed of distinct elements:
(1) Beams and girders—members carrying lateral loads in
bending and shear;
(2) Ties—members carrying axial loads in tension;
(3) Struts, columns or stanchions—members carrying axial
loads in compression. These members are often subjected to
bending as well as compression;
(4) Trusses and lattice girders—framed members carrying
lateral loads. These are composed of struts and ties;
(5) Purlins—beam members carrying roof sheeting;
(6) Sheeting rails—beam members supporting wall cladding;
(7) Bracing—diagonal struts and ties that, with columns and
roof trusses, form vertical and horizontal trusses to resist
wind loads and hence provided the stability of the building.