The shear panel design strength, φQsy must be greater than the seismic story shear, Vx and additional

t

shear force due to torsion, Qsi for all shear panels resisting in the frame of the building for which these

forces are applied. This is expressed as:

W

= φt ∑ nsbs t sFsy

≥ Vx + Qsi

φtQsy

(Eq C-34)

2

H + W

2

The number of shear panels, panel width, height, and strap size and strength shall be designed

according to Equation C-34 to meet minimum lateral yield capacity. All diagonal strap material must be

ASTM A653 steel. Diagonal straps may not use re-rolled steel, because the re-rolling strain hardens the

material, increasing material strength variability and reducing elongation (see USACERL TR FL-XX,

Chapter 4 for a discussion of this concern).

C13. COLUMN AXIAL CAPACITY. The column axial design strength, P shall be determined as follows

for columns built-up with cold-formed steel studs or individual structural tubing members (AISI, C4,

Concentrically Loaded Compression Members):

P = φc A eFn

(Eq C-35)

Where:

φ = the resistance factor for compression, which equals 0.85.

c

Ae = the effective area at the stress Fn.

Fn = the nominal strength of the column, determined as follows:

For λ ≤ 1.5

c

2

Fn = (0.658 λc )Fcy

(Eq C-36)

For λc > 1.5

0.877

Fn = 2 Fcy

(Eq C-37)

λc

Where:

Fcy

λc =

(Eq C-38)

Fe

Where:

Fcy = the column design yield strength.

π2E

Fe =

(Eq C-39)

(KL r )

2

Where:

E = the modulus of elasticity.

K = the effective length factor.

L = the unbraced length of the column.

r = the radius of gyration of the full, unreduced column cross section, calculated as follows:

C-10

Integrated Publishing, Inc. |