Pvy max db

MA -

2

2

PM =

(Eq 3-27)

db

2

Where:

MA = the plastic moment capacity of the angle and plate resting over the horizontal leg of the

angle

db = the distance from the plate edge where the angle corner begins to the critical bending plane

in the plate. The critical bending plane is at the edge of the anchor bolt nut(s) nearest to the

columns.

The plastic moment capacity of the angle and plate, MA is calculated as follows:

(

)

bc 2

MA = φbFAy

tA + t2

(Eq 3-28)

p

4

Where:

FAy = the yield strength of the angle and plate.

bc = the length of the angle, which equals the anchor width and out-of-plane width of the column.

tA = the thickness of the angle.

tp = the thickness of the plate.

The distance from the plate edge to the critical bending plane, db is determined as follows:

W

db = dc - k -

(Eq 3-29)

2

Where:

dc = the distance from the center of anchor bolts to the column face.

k = the distance from the corner of the angle to the flat portion of the angle legs (from AISC

LRFD, Dimensions and Properties of Structural Shapes).

W = the width across flats of the anchor bolt nut(s). This dimension is given in AISC LRFD,

Volume II Connections, Table 8-2, Dimensions of High-Strength Fasteners.

The column moment connection capacity, Mc is defined as follows:

Mc = PM (hc + t A + k )

(Eq 3-30)

Where:

hc = the depth or in-plane width of the column.

A portion of this moment is used to resist the moment created by the eccentric loading of diagonal strap-

to-column connection with respect to the center of the column anchor, PsymaxLs. The angle uplift capacity

that remains to resist column bending, Pcb shall be greater than zero and is determined as follows:

Mc - Psy max L s

Pcb =

(Eq 3-31)

hc + t A + k

3-14

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