V. AISC LRFD - Wide Flange Tension Capacity
To check the adequacy of a W8X24 American section to carry a tensile design load of 245 Kips.
Reference
Hand calculation using the following reference:
AISC Load Factor Resistance Design, 3rd Edition, Example 3.1, case (a), page 3-5.
Problem
Assume the reduction in area due to bolt holes to be equivalent to a net section factor of 0.72.
Hand Calculation
Net section = 0.72(7.08in.2) = 5.11 in.2
Comparison
The reported STAAD.Pro value is based on the term PNT
in the STAAD.Pro output.
Result Type | Theory | STAAD.Pro | Difference | |
---|---|---|---|---|
Design strength (kips) | 248.5 | 248.51 | none |
Note: The assumed NSF of 0.72 is comparable to the term Ae/Ag which evaluates to 5.11/7.08.
STAAD Input
The file C:\Users\Public\Public Documents\STAAD.Pro 2024\Samples \Verification Models\09 Steel Design\US\AISC\AISC LRFD - Wide Flange Tension Capacity.STD is typically installed with the program.
STAAD SPACE TENSION CAPACITY PER AISC LRFD 3RD ED
START JOB INFORMATION
ENGINEER DATE 23-Sep-18
END JOB INFORMATION
*
* OBJECTIVE : CHECKING THE DESIGN AXIAL TENSILE STRENGTH OF A
* W8X24 AMERICAN SECTION. CAPACITY SHOULD BE 245 KIPS ACCORDING TO
* EXAMPLE 3-1 ON PAGE 3-5 OF 3RD EDITION LRFD CODE.
*
UNIT FEET KIP
JOINT COORDINATES
1 0 0 0; 2 10 0 0;
MEMBER INCIDENCES
1 1 2;
MEMBER PROPERTY AMERICAN
1 TABLE ST W8X24
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 FIXED
LOAD 1
JOINT LOAD
2 FX 245
PERFORM ANALYSIS
UNIT INCHES KIP
PARAMETER 1
CODE LRFD
* NSF = 5.11/7.08 = 0.72
NSF 0.72 ALL
FYLD 50 ALL
FU 65 ALL
TRACK 1 ALL
CHECK CODE ALL
FINISH
STAAD Output
STAAD.Pro CODE CHECKING - (LRFD 3RD EDITION) v1.0
***********************
ALL UNITS ARE - KIP INCH (UNLESS OTHERWISE Noted)
MEMBER TABLE RESULT/ CRITICAL COND/ RATIO/ LOADING/
FX MY MZ LOCATION
=======================================================================
1 ST W8X24 (AISC SECTIONS)
PASS LRFD-H1-1A-T 0.986 1
245.00 T 0.00 0.00 0.00
+---------------------------------------------------------------------+
| DESIGN STRENGTHS FOR MEMBER 1 UNITS - KIP IN |
| PNC= 200.22 PNT= 248.51 MNZ= 930.59 MNY= 380.08 VN= 52.46 |
+---------------------------------------------------------------------+