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V. AISC LRFD - Tee Section Compression Capacity

To find a suitable American T-section with an axial compressive strength of 100 Kips.

Reference

Hand calculation using the following reference:

AISC Load Factor Resistance Design, 3rd Edition, Example 4.4, page 4-13.

Problem

The member ends are pinned, and the member is braced at the ends only for both axes.

Fy = 50 ksi

Length = 20 ft

Comparison

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

Table 1. Comparison of results
Result Type Theory STAAD.Pro Difference
Design strength (kips) 102 101.56 none

STAAD Input

The file C:\Users\Public\Public Documents\STAAD.Pro CONNECT Edition\Samples\ Verification Models\09 Steel Design\US\AISC\LRFD 3rd Edition\AISC LRFD - Tee Section Compression Capacity.STD is typically installed with the program.

STAAD SPACE AXIAL COMPRESSION CAPACITY PER AISC LRFD 3RD ED
START JOB INFORMATION
ENGINEER DATE 23-Sep-18
END JOB INFORMATION
*
*  EXAMPLE PROBLEM 4.4, PAGE 4-13, AISC LRFD 3RD ED.
*  CAPACITY (PNC) SHOULD BE ABOUT 102 KIPS
*
UNIT FEET KIP
JOINT COORDINATES
1 0 0 0; 2 0 20 0;
MEMBER INCIDENCES
1 1 2;
MEMBER PROPERTY AMERICAN
1 TABLE T 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 FY MX MZ
LOAD 1
JOINT LOAD
2 FY -100
PERFORM ANALYSIS
UNIT INCHES KIP
PARAMETER 1
CODE LRFD
FYLD 50 ALL
TRACK 1 ALL
SELECT ALL
FINISH

STAAD Output

                       STAAD.Pro MEMBER SELECTION - (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  T    W14X53                   (AISC SECTIONS)
                           PASS     LRFD-H1-1A-C       0.985         1
                      100.00 C          0.00           0.00        0.00
 +---------------------------------------------------------------------+
 | DESIGN STRENGTHS FOR MEMBER     1       UNITS - KIP IN              |
 | PNC=  101.56  PNT=  351.00  MNZ=  209.89  MNY=  322.15  VN=   69.43 |
 +---------------------------------------------------------------------+