# 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.

 Fy =50 ksi

 L =10ft

## Hand Calculation

Net section = 0.72(7.08in.2) = 5.11 in.2

$ϕ P n = { ϕ t F y A g = 0.9 ( 50 k s i ) ( 7.08 i n . 2 ) = 318.6 k ϕ t F u A e = 0.75 ( 65 k s i ) ( 5.11 i n . 2 ) = 248.5 k$

## Comparison

The reported STAAD.Pro value is based on the term PNT in the STAAD.Pro output.

Table 1. Comparison of results
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.

The file C:\Users\Public\Public Documents\STAAD.Pro CONNECT Edition\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
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.Pro CODE CHECKING - (LRFD 3RD EDITION)   v1.0
***********************
ALL UNITS ARE - KIP  INCH (UNLESS OTHERWISE Noted)