V. AISC LRFD - Angle Section Tension Capacity
To check the adequacy of a L4X4X1/2 American single angle to carry a tensile design load of 120 Kips.
Reference
Hand calculation using the following reference:
AISC Load Factor Resistance Design, 3rd Edition, Example 3.2, case (a), page 3-7.
Problem
Assume the reduction in area due to bolt holes to be equivalent to a net section factor of 0.795.
Hand Calculation
Net section = 0.795(3.75 in.2) = 2.98 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) | 121.5 | 121.5 | none |
Note: The assumed NSF of 0.795 is comparable to the term Ae/Ag which evaluates to 2.98/3.75.
STAAD Input
The file C:\Users\Public\Public Documents\STAAD.Pro 2024\Samples \Verification Models\09 Steel Design\US\AISC\AISC LRFD - Angle Section 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
* L4X4X1/2 AMERICAN SECTION. CAPACITY SHOULD BE 122 KIPS ACCORDING TO
* EXAMPLE 3-2 ON PAGE 3-7 OF 3RD EDITION LRFD CODE.
*
UNIT FEET KIP
JOINT COORDINATES
1 0 0 0; 2 0 10 0;
MEMBER INCIDENCES
1 1 2;
MEMBER PROPERTY AMERICAN
1 TABLE ST L40408
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 FY 120
PERFORM ANALYSIS
UNIT INCHES KIP
PARAMETER 1
CODE LRFD
FU 58 ALL
* NSF = 2.98/3.75 = 0.795
NSF 0.795 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 L40408 (AISC SECTIONS)
PASS LRFD-H1-1A-T 0.988 1
120.00 T 0.00 0.00 0.00
+---------------------------------------------------------------------+
| DESIGN STRENGTHS FOR MEMBER 1 UNITS - KIP IN |
| PNC= 34.36 PNT= 121.50 MNZ= 96.57 MNY= 134.69 VN= 25.92 |
+---------------------------------------------------------------------+