To select the lightest ASTM A992 W14 section capable of carrying an axial compression plus biaxial bending.
Reference
AISC Load Factor Resistance Design, 3rd Edition, Example 6.4, page 6-9.
Problem
Muy = 80 ft·kips, Muz = 250 ft·kips | |
Reverse curvature bending with equal end moments for both axis.
Comparison
Table 1. Comparison of results
Result Type |
Theory |
STAAD.Pro
|
Difference |
Selection section |
W14x99 |
W14x99 |
none |
STAAD Output
AXIAL COMPRESSION + BIAXIAL BENDING PER AISC LRFD 3RD ED -- PAGE NO. 3
STAAD.PRO MEMBER SELECTION - (LRFD 3RD EDITION) v1.0
***********************************************
|--------------------------------------------------------------------------|
| Y PROPERTIES |
|************* | IN INCH UNIT |
| * |=============================| ===|=== ------------ |
|MEMBER 1 * | AISC SECTIONS | | AX=0.2910E+2 |
| * | ST W14X99 | | --Z AY=0.6887E+1 |
|DESIGN CODE * | | | AZ=0.1518E+2 |
| LRFD 2001 * =============================== ===|=== PY=0.8360E+2 |
| * PZ=0.1730E+3 |
| * |<---LENGTH (FT)= 14.00 --->| RY=0.3717E+1 |
|************* RZ=0.6176E+1 |
| |
| 250.0 (KIP-FEET) |
|PARAMETER | L1 L1 L1 CAPACITIES |
|IN KIP INCH | L1 L1 L1 IN KIP INCH |
|--------------- + L1 L1 L1 -------------|
| KL/R-Y= 45.20 | L1 L1 L1 PNC=0.1065E+4|
| KL/R-Z= 27.20 + L1 L1 L1 pnc=0.4000E+3|
| UNL = 168.00 |L1 L1 L1 L1 L1 L1 L1 L1 PNT=0.1310E+4|
| CB = 1.00 +L1 L1 L1 L1 L1 L1 L1 L1 pnt=0.0000E+0|
| PHIC = 0.85 |L1 L1 L1 L1 L1 L1 L1 L1 MNZ=0.7717E+4|
| PHIB = 0.90 +L1 L1 L1 L1 L1 L1 L1 L1 mnz=0.3000E+4|
| FYLD = 50.00 |L1 L1 L1 L1 L1 L1 L1 L1 MNY=0.3698E+4|
| NSF = 1.00 +---+---+---+---+---+---+---+---+---+---| mny=0.9600E+3|
| DFF = 0.00 250.0 VN =0.1859E+3|
| dff = 0.00 ABSOLUTE MZ ENVELOPE vn =0.0000E+0|
| (WITH LOAD NO.) |
| |
| MAX FORCE/ MOMENT SUMMARY (KIP-FEET) |
| ------------------------- |
| |
| AXIAL SHEAR-Y SHEAR-Z MOMENT-Y MOMENT-Z |
| |
| VALUE 400.0 0.0 0.0 80.0 250.0 |
| LOCATION 0.0 0.0 0.0 0.0 0.0 |
| LOADING 1 0 0 1 1 |
| |
|**************************************************************************|
|* *|
|* DESIGN SUMMARY (KIP-FEET) *|
|* -------------- *|
|* *|
|* RESULT/ CRITICAL COND/ RATIO/ LOADING/ *|
| FX MY MZ LOCATION |
| ====================================================== |
| PASS LRFD-H1-1A-C 0.951 1 |
| 400.00 C -80.00 -250.00 0.00 |
|* *|
|**************************************************************************|
| |
|--------------------------------------------------------------------------|