The AISC Section Properties database (aiscrev9.dbf) file contains the section properties as described in the AISC manuals. The database file has three 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
Variable Explanations
All dimensions are in inches and kips. These variables are taken from the AISC manuals. These values are not 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, (for example, 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:FYPPPA:
- FYPPPL: Fy ''' (LRFD), See above.
- H: H, flexural constant LRFD Formula (A-E3-9)
- 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 mid-depth
- 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 (F1-8)
- X2: X2, beam buckling factor LRFD Formula (F1-9)
- 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
- A3.1, J1.11 and M2.2 and corresponding Commentary sections).
Note: Type 4 and Type 5 shapes are 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.
Section Notation
- For W, M, HP, C, MC, WT, MT, ST, and S use:(SECTION NAME) X (DN) X (WGT) for example, W36.00X300.00
- For L, 2L (double angles) and TS (structural tubing) use:(SECTION NAME) X (VL) X (HL) X (T) for example, L7.000 X 4.000 X 0.25
- For P, PX and PXX (pipe, strong, extra strong) use: (SECTION NAME) X (DN) X (T) for example, P2.00 X 0.875
Note: All the records in the AISC .dbf files are locked for the cross -sectional libraries. The cross-sectional library cannot change any records in case you want to change the values). However, it does not apply to any library created through the cross-sectional libraries.
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 cross-section 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).