V. EC3 - Pinned column using non-slender UKC section
Verify the design of a pinned column per the EC3 2005 design code.
Details
The column is 8 m with pinned ends. The member is a 305 x 305 x 97 UKC shape with S275 grade steel. The axial load is 2,000 kN and Lcry/L =0.7.
Partial safety factors:
Validation
Effective Length Calculations
Yield Strength
Steel grade S275
The maximum thickness = 15.4 mm < 40 mm; therefore fy = 275 N/mm2 [EN 1993-1-1:2005 Table 3.1]
Section Classification
Outstanding flange (flange under uniform compression):
Class 2 element [EN 1993-1-1:2005 Table 5.2 Sheet 2]
Internal compression part (web in bending):
Class 1 element [EN 1993-1-1:2005 Table 5.2 Sheet 1]
Therefore, section is a Class 2 section.
Axial Resistance
Design axial resistance:
Lateral Buckling
Determine the elastic critical moment, Mcr :
Critical Ratio
Results
Result Type | Reference | STAAD.Pro | Difference | Comments |
---|---|---|---|---|
Critical Ratio | 0.925 | 0.925 | none |
STAAD Input
The file C:\Users\Public\Public Documents\STAAD.Pro 2024\Samples \Verification Models\09 Steel Design\Europe\EC3 - Pinned column using non-slender UKC section.STD is typically installed with the program.
STAAD PLANE
START JOB INFORMATION
ENGINEER DATE 04-Jan-08
END JOB INFORMATION
INPUT WIDTH 79
UNIT METER KN
JOINT COORDINATES
1 0 0 0; 2 0 8 0;
MEMBER INCIDENCES
1 2 1;
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 UC305X305X97
CONSTANTS
MATERIAL STEEL ALL
SUPPORTS
1 PINNED
2 FIXED BUT FY MX MY MZ
LOAD 1 LOADTYPE None TITLE LOAD CASE 1
JOINT LOAD
2 FY -2000
PERFORM ANALYSIS
PARAMETER 1
CODE EN 1993-1-1:2005
SGR 1 ALL
LY 5.6 ALL
GM1 1 ALL
GM0 1 ALL
TRACK 2 ALL
CHECK CODE ALL
FINISH
STAAD Output
STAAD.PRO CODE CHECKING - EN 1993-1-1:2005
********************************************
NATIONAL ANNEX - NOT USED
PROGRAM CODE REVISION V1.14 BS_EC3_2005/1
STAAD PLANE -- PAGE NO. 3
ALL UNITS ARE - KN METE (UNLESS OTHERWISE Noted)
MEMBER TABLE RESULT/ CRITICAL COND/ RATIO/ LOADING/
FX MY MZ LOCATION
=======================================================================
1 ST UC305X305X97 (BRITISH SECTIONS)
PASS EC-6.3.1.1 0.925 1
2000.00 C 0.00 0.00 0.00
=======================================================================
MATERIAL DATA
Grade of steel = S 275
Modulus of elasticity = 205 kN/mm2
Design Strength (py) = 275 N/mm2
SECTION PROPERTIES (units - cm)
Member Length = 800.00
Gross Area = 123.00 Net Area = 123.00
z-axis y-axis
Moment of inertia : 22200.002 7310.001
Plastic modulus : 1590.000 726.000
Elastic modulus : 1442.027 478.873
Shear Area : 87.826 35.174
Radius of gyration : 13.435 7.709
Effective Length : 800.000 560.000
DESIGN DATA (units - kN,m) EUROCODE NO.3 /2005
Section Class : CLASS 2
Squash Load : 3382.50
Axial force/Squash load : 0.591
GM0 : 1.00 GM1 : 1.00 GM2 : 1.25
z-axis y-axis
Slenderness ratio (KL/r) : 59.5 72.6
Compression Capacity : 2677.4 2161.6
Tension Capacity : 3382.5 3382.5
Moment Capacity : 437.3 199.7
Reduced Moment Capacity : 202.6 156.4
Shear Capacity : 1394.4 558.5
BUCKLING CALCULATIONS (units - kN,m)
Lateral Torsional Buckling Moment MB = 307.5
co-efficients C1 & K : C1 =1.132 K =1.0, Effective Length= 8.000
Lateral Torsional Buckling Curve : CURVE b
Elastic Critical Moment for LTB, Mcr = 442.5
Compression buckling curves: z-z: Curve b y-y: Curve c
Critical Load For Torsional Buckling, NcrT = 5058.6
Critical Load For Torsional-Flexural Buckling, NcrTF = 5058.6
STAAD PLANE -- PAGE NO. 4
CRITICAL LOADS FOR EACH CLAUSE CHECK (units- kN,m):
CLAUSE RATIO LOAD FX VY VZ MZ MY
EC-6.3.1.1 0.925 1 2000.0 0.0 0.0 0.0 0.0
Torsion has not been considered in the design.
_________________________
************** END OF TABULATED RESULT OF DESIGN **************