Design of a T-beam - Reinforced Concrete with FRP Bars: Mechanics and Design - page 271

T f2II (x) := A f2II ·E f ·ε f2II (x)

The neutral axis depth, c u , can be computed by solving the equation of
equilibrium C c - T f = 0:
First guess:

x 02 := 0.1d f2

Given:

f 2 (x):= C c2 (x) - (T f2I (x) + T f2II (x))

c u2 := root(f 2 (x 02 ),x 02 )

The neutral axis depth is

c u2 = 2.458·in.

Check_NetralAxisDepth : =

“The neutralaxisfalls within theflangedepth”ifc ≤ t

u2 slab

“A T-sectionanalysishas to be conducted” otherwise

Check_NetralAxisDepth = “The neutral axis falls within the flange depth”

The nominal bending moment capacity can be computed as follows:

( )

⋅ ε

c y

c2 u2

2" ⋅σ

c

ε

c

u2

∫

c0

( )

( )

M:b ⋅ y ⋅ psidyT c + ⋅ dc −

=

n2 eff f2I u2 f2I u2

2

( )

0

ε c y

c2 u2

1 +

ε

c0

( )

( )

+ Tc dc ⋅ −

f2II u2 f2II u2

M n2 = 776·kip·ft

The strain distribution over the cross section is shown next.