Beam Design
North Carolina State University
CE 466 Building Construction Engineering

Beam Design

Beam Design
•
Approach for beam design?
•
What criteria will you consider for beam design?
a)
Bending
b)
Shear
c)
Deflection
d)
Bearing

Allowable Stresses
“Resistance”
Stresses Imposed by Load
F
b
’ = F
b
*C
D
*C
M
*C
t
*C
L
*C
F
*C
fu
*C
i
*C
r
ƒ
b
= M*y/I
F
t
’ = F
t
*C
D
*C
M
*C
t
*C
F
*C
i
ƒ
t
= P/A
net
F
v
’ = F
v
*C
D
*C
M
*C
t
*C
i
ƒ
v
= V*Q / (I*b)
F
c
’ = F
c
*C
D
*C
M
*C
t
*C
F
*C
i
*C
P
ƒ
c
= P/A
F
c┴
’ = F
c┴
*C
M
*C
t
*C
i
ƒ
c┴
= P/A
┴
E’ = E*C
M
*C
t
*C
i
Δ
E
min
’ = E
min
*C
M
*C
t
*C
i
*C
T
C
P
≥
Beam Design

Bending
•
Bending Stress:
Eqn 3.3-1
ASD
LRFD
?
?
≤
?
′
?
❑

Bending
•
Adjusted Stress
F'
b
=F
b
C
D
C
M
C
t
C
L
C
F
C
fu
C
i
C
r
(ASD)
F'
b
=F
b
φ
b
λ C
M
C
t
C
L
C
F
C
fu
C
i
C
r
K
F
(LRFD)

Bending
•
Beam Stability factor (C
L
)
F'
b
=F
b
C
D
C
M
C
t
C
L
C
F
C
fu
C
i
C
r
(ASD)
What is the normal case?
- Lateral torsional buckling
C
L
= 1
Sec. 3.3.3

Bending
•
Beam Stability factor (C
L
)
C
L
1
Sec. 3.3.3
d
b
d
b
C
L
1

Bending
•
Beam Stability factor (C
L
)
Sec. 3.3.3
where F
b
* =
F
b
times all
C
applicable except
C

#### You've reached the end of your free preview.

Want to read all 15 pages?

- Summer '20
- Buckling, Beam Design