Lecturenotes lesson1 introduction to steel building structures

Assoc Prof Dr Nguyen Trung Kien Email kiennthcmute edu vn Faculty of Civil Engineering February 2020 DESIGN OF STEEL STRUCTURES II 2 CONTENT  Overview on steel structures and application  Design of single span steel portal frames  Design of wide span steel buildings  Design of multi storey steel buildings 3 REFERENCES Text books  Nageim and MacGinley, Steel structures – Practical design studies, 3rd Edition, Taylor Francis, 2005  Elastic design of single span steel portal frame building.

Assoc Prof Dr Nguyen Trung Kien Email: kiennt@hcmute.edu.vn Faculty of Civil Engineering

February 2020

 Overview on steel structures and application

 Design of single-span steel portal frames

 Design of wide-span steel buildings

 Design of multi-storey steel buildings

studies, 3rd Edition, Taylor & Francis, 2005

 Elastic design of single-span steel portal frame buildings to Eurocode 3, SCI, 2012

References:

 Trahair et al., The behaviour and design of steel structures to EC3, 4th Edition, Taylor & Francis, 2008

 TCVN 5575-2012 : Steel structures – Design standard

 TCVN 2737-1995: Loads and action on the buildings

 Overview on steel structures and application

 Design of single-span steel portal frames

 Design of wide-span steel buildings

 Design of multi-storey steel buildings

LESSON 1

OVERVIEW ON STEEL STRUCTURES

 PROPERTIES OF STEEL STRUCTURES

 High strength and reliability

 High yield stress: fy=200 - 320Mpa

 Ease of fabrication and mass production

 Fast and easy erection and installation

 Substantial elimination of delays due to weather

 More accurate detailing

 Nonshrinking and noncreeping at ambient temperature

 Corrosion

DISADVANTAGES:

Classification according to chemical components:

 Structural steel material: low carbon steel (C=0,05-0,3%) by soft, easy tohandle and forging properties

• Alloy steel: Steel + Cr, Ni, Mn, … to improve its mechanical properties

Classification according to deoxidation: boiling, semi-static and static steel

Iron ore (Fe2O3, Fe3O4…)

 Construction steel material:

 3 deoxidated levels : boil, semi-static (n), static

 Group C : assured chemical and mechanical properties

 C : Group C for construction structures

 CT : lower carbon

 38 : ultimate resistance 38 KN/cm2 = 380Mpa

 n : semi-static (deoxidation level)

 Relation of tensile stress and strain

2 STEEL MATERIALS

E: Young’s modulus

fy : yield stress

fu: ultimate stress

 Physical properties of steel

 Other steel materials

 Other steel materials

2 STEEL MATERIALS

f f





u c

M

f f





Angle (L-shaped cross section)

 Uniform sides (Fig a): L20x3

I-cross section (TCVN 1655-75)

 I30 - I60

C-cross section (TCVN 1654-75)

 C5 - C40

3 STRUCTURAL STEEL PROFILES

 Other cross sections

 Cold rolled steel

Cold rolled steel coil

3 STRUCTURAL STEEL PROFILES

 Structural design process

 Limit state theory and design codes

 Ultimate limit state

 Serviceability limit state

 TCVN 5575 – 2012 & Eurocode 3, 4

4 STEEL STRUCTURAL DESIGN

 Industrial buildings

Phu tho indoor building, L=100m

San siro stadium

 Wide-span buildings

5 APPLICATIONS

Millennium Tower (Vienna – Austria) Diamond plaza (HCMC)

 High-rise buildings

Eiffel tower - Paris

 Towers

5 APPLICATIONS

 Oil tanks and pipes

Viaduc Gabarit (France) built by Gustave Eiffel – 1884 (Span L=165m)

 Steel bridges

5 APPLICATIONS

 Drilling platform structures

Important points

Steel material Concrete material

Important points

3 Steel structural profiles

Hot-rolled steel section

Cold-rolled steel section

Primary structures

Secondary structures

4 Connection

Welded connection

Bolted connection

Butt & fillet welding

Common & high-strength bolts

Important points 4.1 CALCULATE WELDED CONNECTIONS:

 Design strength of butt weld : fwc, fwt, fwv

 Compressive strength: fwc=f

 Tensile strength: fwt=f (ultrasonic test), fwt=0.85f

(normal inspection)

 Shear strength: fwv=fv=0.58f

 Design strength of fillet weld : fwf, fws

 fwf : shear strength (fracture plane 1)

 fws=0.45fu : shear strength (fracture plane 2)

Important points

5 Steel beams

Built-up section Rolled section

VS h

M f

Important points

Local buckling in flange

Local buckling in web

Important points

Important points

7 Steel truss





Select the section 

c

N

f A

N

f A

Change the section

ok

not okCompression truss element:

Important points 7 Verification of steel truss members

req

c

N A

f





Select the section 

N

f A

ok

not okTension truss element:

8 Composite structures

Composite column Composite slab

Composite beam

Important points

9 Application

Multi-storey buildings Industrial buildings

Wide-span buildings

Industrial buildings

9.1

Indoor building structures Canopy structures

Multi-storey buildings

9.3