V. AISC LRFD - Select Wide Flange 1
To select the optimum ASTM A992 W-shape with a design flexural strength of 500 kip-ft.
Reference
AISC Load Factor Resistance Design, 3rd Edition, Table 5.2, , page 5-50.
Problem
Beam is bent about its strong axis, and is continuously braced.
Comparison
Result Type | Theory | STAAD.Pro | Difference |
---|---|---|---|
Optimum section | W24x55 | W24x55 | none |
Design strength, ϕbMz (ft·kips) | 506 | 502.5 (*) | <1% |
* Calculated as MZ envelope value divided by the MZ ratio:
499.95 ft·kips/0.995 = 502.5 ft·kips
Note: Fully braced condition can be achieved by setting the
UNT
parameter equal to 1.0 inch.STAAD Input
The file C:\Users\Public\Public Documents\STAAD.Pro 2024\Samples \Verification Models\09 Steel Design\US\AISC\AISC LRFD - Select Wide Flange 1.STD is typically installed with the program.
STAAD SPACE BENDING CAPACITY PER AISC LRFD 3RD ED
START JOB INFORMATION
ENGINEER DATE 23-Sep-18
END JOB INFORMATION
*
* TABLE 5.2, PAGE 5-40, AISC LRFD 3RD ED.
* OBJECTIVE : TO SELECT THE MOST OPTIMUM SECTION WITH A DESIGN
* FLEXURAL STRENGTH OF 500 KIP-FT.
* FOR A FULLY BRACED BEAM, PER ABOVE REFERENCE, IT SHOULD BE
* A W24X55
*
* 500 KIP-FT IS EQUAL TO AN APPLIED LOAD OF 4.444 KIP/FT ON
* A SIMPLY SUPPORTED BEAM
*
UNIT FEET KIP
JOINT COORDINATES
1 0 0 0; 2 30 0 0;
MEMBER INCIDENCES
1 1 2;
MEMBER PROPERTY AMERICAN
1 TABLE ST W12X26
UNIT INCHES KIP
DEFINE MATERIAL START
ISOTROPIC MATERIAL1
E 29000
POISSON 0.3
END DEFINE MATERIAL
UNIT FEET KIP
CONSTANTS
MATERIAL MATERIAL1 ALL
SUPPORTS
1 PINNED
2 FIXED BUT MZ
LOAD 1
MEMBER LOAD
1 UNI GY -4.444
PERFORM ANALYSIS
UNIT INCHES KIP
PARAMETER 1
CODE LRFD
* FULLY BRACED CONDITION IS ACHIEVED WITH A UNT OF 1.0 INCH
UNT 1 ALL
MAIN 1 ALL
FYLD 50 ALL
CB 0 ALL
TRACK 2 ALL
SELECT ALL
FINISH
STAAD Output
STAAD.PRO MEMBER SELECTION - (LRFD 3RD EDITION) v1.0
***********************************************
|--------------------------------------------------------------------------|
| Y PROPERTIES |
|************* | IN INCH UNIT |
| * |=============================| ===|=== ------------ |
|MEMBER 1 * | AISC SECTIONS | | AX=0.1620E+2 |
| * | ST W24X55 | | --Z AY=0.9322E+1 |
|DESIGN CODE * | | | AZ=0.4720E+1 |
| LRFD 2001 * =============================== ===|=== PY=0.1330E+2 |
| * PZ=0.1340E+3 |
| * |<---LENGTH (FT)= 30.00 --->| RY=0.1340E+1 |
|************* RZ=0.9129E+1 |
| |
| 499.9 (KIP-FEET) |
|PARAMETER | L1 L1 L1 CAPACITIES |
|IN KIP INCH | IN KIP INCH |
|--------------- + L1 L1 -------------|
| KL/R-Y= 268.60 | PNC=0.4791E+2|
| KL/R-Z= 39.44 + L1 L1 pnc=0.0000E+0|
| UNL = 1.00 | PNT=0.7290E+3|
| CB = 1.14 + L1 L1 pnt=0.0000E+0|
| PHIC = 0.85 | MNZ=0.6030E+4|
| PHIB = 0.90 + mnz=0.5999E+4|
| FYLD = 50.00 |L0 L0 MNY=0.5604E+3|
| NSF = 1.00 +---+---+---+---+---+---+---+---+---+---| mny=0.0000E+0|
| DFF = 0.00 -27.8 VN =0.2517E+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 0.0 66.7 0.0 0.0 499.9 |
| LOCATION 0.0 0.0 0.0 0.0 15.0 |
| LOADING 0 1 0 0 1 |
| |
|**************************************************************************|
|* *|
|* DESIGN SUMMARY (KIP-FEET) *|
|* -------------- *|
|* *|
|* RESULT/ CRITICAL COND/ RATIO/ LOADING/ *|
| FX MY MZ LOCATION |
| ====================================================== |
| PASS LRFD-H1-1B-C 0.995 1 |
| 0.00 C 0.00 -499.95 15.00 |
|* *|
|**************************************************************************|
| |
|--------------------------------------------------------------------------|