Section 5
5-73
5.20.2 Prismatic Property Specification
Purpose
The following commands are used to specify section properties for
prismatic cross-sections.
General format:
For the PRISMATIC specification, properties are provided directly
(End each line but last with a hyphen “-”) as follows:
*
⎧
AX f⎫
1
⎪
IX f⎪
2
⎪
IY f⎪
3
⎪
IZ f⎪
T-SECTION TRAPEZOIDAL SECTION
ZD
YD
ZB
YB
ZD
YD
ZB
4
property-spec =
⎨
AY f⎬
5
⎪
AZ f⎪
6
⎪
YD f⎪
7
⎪
ZD f⎪ See Section 1.7.1
8
⎪
YB f⎪
9
⎩
ZB f
10
⎭
Figure 5.11
AX f
1
= Cross sectional area of the member. Set to zero for TEE,
Rectangular, Trapezoid, or circular.
IX f
2
= Torsional constant.
IY f
3
= Moment of inertia about local y-axis.
IZ f
4
= Moment of inertia about local z-axis (usually major).
AY f
5
= Effective shear area in local y-axis.
AZ f
6
= Effective shear area in local z-axis.
If any of the above 6 parameters are omitted, it will be calculated
from the YD, ZD, YB, and/or ZB dimensions.
