V. AISC LRFD - Select Wide Flange 2
To find the optimum W shape with a flexural design strength of 150 ft·kips. Beam is braced at ends and at mid-span point.
Problem
The beam should also satisfy a deflection limit of 1.0 inches under service load.
| Fy = 50 ksi |
| Length = 20 ft |
| Lb = 10 ft |
Service load of 2.0 kip/ft. Deflection limit under service load = 1.0 in.
Comparison
The reported STAAD.Pro value is based on the term MNZ in the STAAD.Pro output.
| Result Type | Theory | STAAD.Pro | Difference |
|---|---|---|---|
| Optimum Section | W16x31 | W16x31 | none |
| Design bending strength, ϕbMn | 150 |
150.17 (1,802 in·kips) |
negligible |
| Maximum permissible deflection (in) | 1.0 | 0.658 | N/A (*) |
STAAD Input
The file C:\Users\Public\Public Documents\STAAD.Pro CONNECT Edition\Samples\ Verification Models\09 Steel Design\US\AISC\AISC LRFD - Select Wide Flange 2.STD is typically installed with the program.
STAAD SPACE BENDING PER AISC LRFD 3RD ED
START JOB INFORMATION
ENGINEER DATE 23-Sep-18
END JOB INFORMATION
*
* EXAMPLE 5.4, PAGE 5-21, AISC LRFD 3RD ED.
* OBJECTIVE : TO FIND THE OPTIMUM W SHAPE WITH A FLEXURAL
* DESIGN STRENGTH OF 150 KIP-FT.
*
* ACCORDING TO ABOVE REFERENCE, THE SECTION SHOULD BE W16X31
*
UNIT FEET KIP
JOINT COORDINATES
1 0 0 0; 2 20 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 -2
LOAD COMBINATION 2
1 1.5
PERFORM ANALYSIS
LOAD LIST 2
UNIT INCHES KIP
PARAMETER 1
CODE LRFD
MAIN 1 ALL
UNT 120 ALL
FYLD 50 ALL
TRACK 1 ALL
SELECT ALL
LOAD LIST ALL
PERFORM ANALYSIS
LOAD LIST 1
SECTION 0.5 ALL
PRINT SECTION DISPL
LOAD LIST 2
CHECK CODE ALL
FINISH