This document provides information about the CEE-312 Structural Analysis and Design Sessional-I course at SUST. The course is worth 1 credit and includes lectures, a mini project, final exam, and class performance evaluation. Reference books and the course syllabus are listed. The document then covers structural elements like tension members, compression members, beams, and sections including channels, angles, and wide flanges. Properties like centroid, moment of inertia, radius of gyration, and section modulus are defined. Structural analysis and design concepts are discussed through examples and diagrams.

1. CEE-312
Structural Analysis and Design Sessional-I
(1.0 credit)
Lecture: 1
Bijit Kumar Banik
Assistant Professor, CEE, SUST
Room No.: 115 (“C” building)
bijit_sustbd@yahoo.com
Department of Civil and Environmental Engineering

2. Industrial Roof Truss Analysis
Syllabus

3. Attendance 10%
Evaluation process
Mini project 30%
Final Exam 40%
Total 100%
Class performance 20%

4. 2. Design of steel structures
– Elias G. Abu-Saba
References
3. Simplified Design of steel structures
– Harry Parker and James Ambrose
4. Strength of materials
– Andrew Pytel and Ferdinand L. Singer
1. Supplied sheet

5. Better quality control
Why steel structures?
Faster to erect
Reduced site time- Fast track construction
Large column free space and amendable for alteration
Lighter
Less material handling at site
Less % of floor area occupied by structural elements
Better lateral and earthquake load resistance

6. Skilled labor is required
Why not?
Higher maintenance cost
Poor fireproofing, as at 10000F (5380C) 65% &
at 16000F (8710C) 15% of strength remains
Higher cost of construction
Electricity may be required

7. Stress-strain diagram
Strain
Stress
A
A = Proportional limit
C
C = Yield Strength
B
B = Elastic limit
D
D = Ultimate Strength
E
E = Rapture Strength
F
F = Actual Rapture Strength
Plastic design
Elastic design

8. Centriod
The centroid of a body is the center of its mass (or masses), the point at which it
would be stable, or balance, under the influence of gravity.
Centriod of a composite structure
5
1
5
1
A1
A2
X
Y
......2211 +×+×=× YAYAYA
Y
Y1=5.5
Y2=2.5
10X = (5X1)X5.5+(5X1)X2.5Y
Y = 4
A = 5X1+5X1=10

9. Double Moment of Area (So called Moment of Inertia)
The Double Moment of Area (I) is a term used to describe the capacity of a
cross-section to resist bending. It is a mathematical property of a section
concerned with a surface area and how that area is distributed about the
reference axis.
dA
X
Y
y
∫= dAyIx
2
x
∫= dAxI y
2

10. Moment of Inertia
For rectangular section
X
Y
h
b
X’
d
A
Transfer formula
2
' AdII xx +=
12
3
bh
Ix =
= Moment of inertial about centroidal X-axis
xI

11. Moment of Inertia
P
4
1
2
8
CA
CA
P
A = 8X2
A = 2X8
1
2
(2) Is 16 times stiffer than (1) !!!

12. Moment of Inertia
d2
d1
12”X1”
I1 = 2850 in4
A1 = 24.8 in2
1
2
26.75”
CA
CA2
CA1
36.8X = 24.8X(26.75/2)+(12X1)X27.25Y
Y = 17.9
Y
A = 24.8+12X1=36.8
={ 2850+24.8*(4.52)2}+{1+12*(9.35)2}
d1= 17.9-26.75/2=4.52
d2= 26.75-17.9+0.5=9.35
I2= (1/12)*12*13=1
= 4407 in4
I = (I1+A1d1
2) + (I2+A2d2
2)

13. Moment of Inertia
Divers reducing their moments
of inertia to increase their rates of
rotation
The deflection of a beam under load depends not only on the load, but also
on the geometry of the beam's cross-section. This is why beams with higher
area moments of inertia, such as I-beams (properly denoted as: wide-flange
beams), are so often seen in building construction as opposed to other
beams with the same cross sectional area.

14. Radius of gyration (r)
Describes the way in which the area of a cross-section is distributed around
its centroidal axis. If the area is concentrated far from the centroidal axis it
will have a greater value of ‘r’ and a greater resistance to buckling.
A
I
r =
where
r = radius of gyration
I = moment of inertia
A = area of the cross section
Folding paper example

15. 8ft
2”
Solid
round rod
4 “
Standard
pipe
Tube
4”X2”X5/16”
Tube
3”X3”X5/16”
Radius of gyration (r)
12.7 k 54 k 28k 44 k
r = 0.5 r = 1.51 r = 0.74 r=1.07
All members has X-sectional area = 3-1/8 in2

16. Section Modulus (Z)
The section modulus of the cross-sectional shape is of significant importance
in designing beams. It is a direct measure of the strength of the beam.
Section modulus Load taking capacity
c
I
Z =
Mathematically can be expressed as
Where, Z = Section modulus
I = Moment of Inertia of area
c = distance from the neutral axis to the remotest element
c

17. Sections

18. Sections

19. Tension members
1. Chord Members in trusses
Vertical Top chord
Diagonal
Bottom chord

20. Tension members
2. Diagonal bracing in bracing systems

21. Tension members
3. Cable elements in suspension roofs, main cables
of suspension bridges and suspenders
The Verrazano-Narrows in USA was the largest from 1964 until 1981.
It serves a main span of 1298 meters. Now 7th.

22. Compression member

23. Compression member
;
–
1. Columns in buildings

24. Compression member
;
–
2. Chord Members in trusses
3. Diagonal members in end panels of trusses

25. Beam member

26. Open web joist

27. Wide flange section
Designation W 10X30
W is the short for Wide-flange
10 is the height (h)
30 is weight per linear length

28. Channel section
Designation C 3X4.1
C is the short for channel
3 is the height (h)
4.1 is weight per linear length

29. Angle section
Designation L 1.5X2X1/8
L denotes angle
1.5 is the height (d)
2 is base length (bw)
1/8 is the thickness(t)

30. AISC chart sample (Wide-flange)
pp- 571-578; Strength of materials-By Singer (4th edition)

31. AISC chart sample (Channel)
pp- 581-582; Strength of materials-By Singer (4th edition)

32. AISC chart sample (Angles)
pp- 583-588; Strength of materials-By Singer (4th edition)

33. Group Formation
Four groups

34. http://www.facebook.com/groups/cee15/