AISC Library
Section 1. Introduction
The AISC Section Properties database (aiscrev9.dbf)
file contains the section properties as described in the AISC manuals.
The database file has 3 fields. The first field contains the name of the
section (see Section 3) and has a width of 30 characters. The second field
(width: 12) describes the property that is assigned to this name. Section
2 describes the symbols used in the second field. The third field (width:
50) contains the value of this property.
There are five general types of sections contained in the file:
Type 1: W, M, S and HP Shapes (I shapes)
Type 2: C and MC Shapes (channels)
Type 3: WT, MT and ST Shapes (tee sections)
Type 4: TS, L and 2L Shapes (structural tubing, single
and double angles)
Type 5: Pipe Shapes
Section 2. Variable Explanations
All dimensions are in inches and kips. These variables are taken from
the AISC manuals. These values will NOT be scaled to the unit system of
your model if you are using a unit other than inch for length or pound
for force.
 A:
Area
 BF:
Width of flange
 BTF:
"bf/2tf", the ratio of the flange width to twice the
flange thickness
 CW:
Cw, warping constant
 D:
Depth, actual
 DAF:
"d/Af", the ratio of the depth to the compression flange area
 DI:
Inner diameter of pipe
 DN:
Nominal depth. Nominal Diameter in case of pipe sections (P, PX, PXX)
 DSG:
Shape designation, i.e. "W" or "C"
 DTW:
"d/tw", the ratio of the depth to the web thickness
 EO:
"eo", distance from outside face of web to shear center
 FYP: "Fy ' ", the theoretical
maximum yield stress based on the widththickness ratio of 1/2 the unstiffened
compression flange, beyond which a particular shape is not compact. (Specified
as 0 if greater than 65 ksi)
 FYPPPA: "Fy ''' "(ASD), the
theoretical maximum yield stress based on the depththickness ratio of
the web below which a particular shape may be considered compact for any
condition of combined bending and axial stresses. (Specified as 0 if greater
than 65 ksi)
 FYPPPL:
"Fy ''' " (LRFD), See above.
 H:
"H", flexural constant LRFD Formula (AE39)
 H38:
"H", flexural constant, double angles 3/8" back
to back
 H34:
"H", flexural constant, double angles 3/4" back
to back
 HL:
Horizontal leg or side dimension
 HTW:
"hc/tw", ratio of assumed web depth for stability to
thickness of web
 JSHP:
JUMBO SHAPE ("J"), See the note at the end of the variable
list.
 NT:
Tensile type number per ASTM A6
 OD:
Outer diameter of pipe
 QF:
"Qf", statical moment at point in flange
 QW:
"Qw", statical moment at middepth
 RA:
Minimum fillet radius, detailing value (in.); flange toe value
for M, S, C and MC shapes
 RI:
Minimum fillet radius, design
 RO:
"ro", shear center coordinate
 RO38:
"ro", double angles 3/8" back to back
 RO34:
"ro", double angles 3/4" back to back
 RT:
The radius of gyration of a section comprising the compression
flange plus 1/3 of the compression web area, taken about an axis in the
plane of the web
 RX:
"rx", radius of gyration about axis XX
 RY:
"ry", radius of gyration about axis YY
 RY38:
"ry", double angles 3/8" back to back
 RY34:
"ry", double angles 3/4" back to back
 RZ:
"rz", radius of gyration about principal axis
 SX:
"Sx", elastic section modulus about axis XX
 SY:
"Sy", elastic section modulus about axis YY
 SW:
"Sw", warping statical moment
 T:
Thickness of leg or wall
 TF:
Thickness of flange
 TW:
Thickness of web
 VL:
Vertical leg or side dimension
 WGT:
Nominal weight
 WNO:
"Wno", normalized warping function
 XB:
"x", centroid of section in X direction from outer web
 XI:
"Ix", moment of inertia about axis XX
 XJ:
"J", torsional constant
 XK:
"k", distance from outer face of flange to web toe fillet
of rolled shape
 X1:
"X1", beam buckling factor LRFD Formula (F18)
 X2:
"X2", beam buckling factor LRFD Formula (F19)
 YB:
"y", centroid of section in Y direction from outer top
flange face
 YI:
"Iy", moment of inertia about axis YY
 ZX:
"Zx", plastic modulus about axis XX
 ZY:
"Zy", plastic modulus about axis YY
 NOTE: Type
4 and Type 5 shapes are generally contemplated for application
as columns or compression components. When used in other applications
(e.g. trusses) and when thermal cutting or welding is required, special
material specification and fabrication procedures apply to minimize the
possibility of cracking (see June 1, 1989 ASD Specification Sects. A3.1,
J1.11 and M2.2 and corresponding Commentary sections).
Section 3. Section Notation

For W, M, HP, C, MC, WT, MT,
ST and S use:
(SECTION NAME) X (DN) X (WGT)
e.g. W36.00X300.00

For L, 2L (double angles) and
TS (structural tubing) use:
(SECTION NAME) X (VL) X (HL)
X (T)
e.g. L7.000 X 4.000 X 0.25
For P, PX and PXX
(pipe, strong, extra strong) use:
(SECTION NAME) X (DN) X (T)
e.g. P2.00 X 0.875
 Note:
All the records
in the AISC .dbf files are locked for the cross sectional libraries (i.e.,
the crosssectional library cannot change any records in case you want
to change the values). However, this does not apply to any library created
through the crosssectional libraries.
Section 4. Unsymmetrical Sections
The AISC section properties database includes the shear center and center
of gravity locations for unsymmetrical sections such as angles and channels.
The current linear beam element does not include twisting due to loadings
which are offset from the shear center. Therefore, the Beam Design Editor
use of the AISC properties ignores the shear center offset from the beam
crosssection center of gravity. It is your responsibility to account
for the effects of shear center offset from the center of gravity.
References
Manual of Steel Construction: Allowable
Stress Design, 9th ed. (Chicago: American Institute of Steel Construction,
Inc., 1989).
Manual of Steel Construction: Load
and Resistance Factor Design, 1st ed. (Chicago: American Institute
of Steel Construction, Inc.,1986).