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.

F_y = 50 ksi

Length = 20 ft

Comparison

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

表 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 2023\Samples \Verification Models\09 Steel Design\US\AISC\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 | 
 +---------------------------------------------------------------------+