V. BS5950 2000 - Pinned Column Using Slender CHS

A 6.0m circular hollow section (CHS) column is pin ended about both axes and has no intermediate restraints.

Reference

Steelwork Design Guide to BS 5950-1:2000, Volume 2, Worked Examples, SCI publication P326, Example 12, The Steel Construction Institute.

Problem

The column is designed in S355 steel for the factored loading.

Point load, F_c = 2,500 kN

Comparison

Table 1. Comparison of results
Result Type	Theory	STAAD.Pro	Difference
Effective area, A_eff (cm²)	77.6	77.63	none
Slenderness, λ	42.2	42.413	none
Compression capacity, P_c (kN-m)	2,561	2,562.3	none

STAAD Input

TRACK 2 ALL: Maximum detail output
SGR 1 ALL: Identifies steel grade as S355

Tip: You can copy and paste this content directly into a .std file to run in STAAD.Pro.

The file C:\Users\Public\Public Documents\STAAD.Pro CONNECT Edition\Samples\ Verification Models\09 Steel Design\UK\BS5950 2000 - Pinned Column Using Slender CHS.STD is typically installed with the program.

STAAD SPACE
START JOB INFORMATION
JOB NAME Example no. 12
JOB CLIENT The Steel Construction Institute
JOB COMMENT Pinned column using a slender CHS.
ENGINEER DATE Jun-2003
END JOB INFORMATION
INPUT WIDTH 79
UNIT METER KN
JOINT COORDINATES
1 0 0 0; 2 0 6 0;
MEMBER INCIDENCES
1 1 2;
*************************************
DEFINE MATERIAL START
ISOTROPIC STEEL
E 2.05e+08
POISSON 0.3
DENSITY 76.8195
ALPHA 1.2e-05
DAMP 0.03
END DEFINE MATERIAL
MEMBER PROPERTY BRITISH
1 TABLE ST PIP4066.3
CONSTANTS
MATERIAL STEEL ALL
SUPPORTS
1 FIXED
*************************************
LOAD 1 AXIAL FORCE
JOINT LOAD
2 FY -2500
PERFORM ANALYSIS PRINT STATICS CHECK
***************************************
PARAMETER 1
CODE BS5950
SGR 1 ALL
TRACK 2 ALL
CHECK CODE ALL
FINISH

STAAD Output

                         STAAD.Pro CODE CHECKING - (BSI )
                         ***********************
  PROGRAM CODE REVISION V2.13_5950-1_2000
      STAAD SPACE                                              -- PAGE NO.    5
 ALL UNITS ARE - KN   METE (UNLESS OTHERWISE Noted)
 MEMBER     TABLE       RESULT/   CRITICAL COND/     RATIO/     LOADING/
                          FX            MY             MZ       LOCATION
 =======================================================================
       1 ST PIP4066.3     PASS     BS-4.7   (C)       0.976         1
                      2500.00 C          0.00           0.00        0.00
 =======================================================================
   MATERIAL DATA                
      Grade of steel           =  S 355
      Modulus of elasticity    =  205 kN/mm2  
      Design Strength  (py)    =  355  N/mm2  
   SECTION PROPERTIES (units - cm)
      Member Length =    600.00
      Gross Area =   79.20  Net Area =   79.20  Eff. Area =   77.63
                                    z-z  axis       y-y  axis
      Moment of inertia        :    15850.002       15850.002
      Plastic modulus          :     1009.000        1009.000
      Elastic modulus          :      780.020         780.020
      Effective modulus        :      780.020         780.020
      Shear Area               :       47.520          47.520
   DESIGN DATA (units - kN,m)   BS5950-1/2000
      Section Class            :   SLENDER     
      Squash Load              :   2811.60
      Axial force/Squash load  :     0.889
                                    z-z  axis       y-y  axis
      Compression Capacity     :       2562.3         2562.3
      Shear Capacity           :       1012.2         1012.2
   BUCKLING CALCULATIONS (units - kN,m)
   (axis nomenclature as per design code)
                                     x-x axis        y-y axis
      Slenderness              :       42.413          42.413
      Radius of gyration (cm)  :       14.147          14.147
      Effective Length         :        6.000           6.000
      LTB check unnecessary for this section
   CRITICAL LOADS FOR EACH CLAUSE CHECK (units- kN,m):
    CLAUSE        RATIO  LOAD     FX       VY      VZ      MZ      MY   
   BS-4.7   (C)   0.976     1  2500.0       -       -       -       - 
    Torsion and deflections have not been considered in the design.
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