V. Column Buckling Factor
Determine the buckling factor for a pinned-pinned column subject to an axial load.
Details
A 30 ft tall column with pinned ends is subject to a 160 kip axial load. The section is a W10x45 with a modulus of elasticity of 29,730 ksi.
STAAD Input
The file C:\Users\Public\Public Documents\STAAD.Pro CONNECT Edition\Samples\Verification Models\07 Nonlinear Analysis\Column Buckling Factor.std is typically installed with the program.
STAAD PLANE : BUCKLING FACTOR FOR PINNED-PINNED COLUMN WITH AN AXIAL LOAD
SET SHEAR
INPUT WIDTH 79
UNIT FEET KIP
JOINT COORDINATES
1 0 0 0 5 0 30 0;
MEMBER INCIDENCES
1 1 2 4
UNIT KIP INCH
DEFINE MATERIAL START
ISOTROPIC STEEL
E 29730
POISSON 0.3
DENSITY 0.286E-3
ALPHA 6e-006
DAMP 0.03
END DEFINE MATERIAL
MEMBER PROPERTY AMERICAN
1 TO 4 TABLE ST W10X45
CONSTANTS
MATERIAL STEEL ALL
SUPPORTS
1 PINNED
5 FIXED BUT FY MX MY MZ
LOAD 1 LOADTYPE None TITLE LOAD CASE 1
JOINT LOAD
5 FY -160
PERFORM BUCKLING ANALYSIS MAXSTEP 20
FINISH
STAAD Output
BUCKLING ITERATIONS FOR CASE NO. 1 ITERATION BUCKLING FACTOR UPPER BOUND LOWER BOUND 0 1.00000000E+00 0.00000000E+00 0.00000000E+00 1 2.00000000E+00 1.01000000E+10 1.00000000E+00 2 4.00000000E+00 1.01000000E+10 2.00000000E+00 3 3.00000000E+00 4.00000000E+00 2.00000000E+00 4 3.50000000E+00 4.00000000E+00 3.00000000E+00 5 3.75000000E+00 4.00000000E+00 3.50000000E+00 6 3.62500000E+00 3.75000000E+00 3.50000000E+00 7 3.56250000E+00 3.62500000E+00 3.50000000E+00 8 3.53125000E+00 3.56250000E+00 3.50000000E+00 9 3.51562500E+00 3.53125000E+00 3.50000000E+00 10 3.50781250E+00 3.51562500E+00 3.50000000E+00 11 3.51171875E+00 3.51562500E+00 3.50781250E+00 12 3.50976562E+00 3.51171875E+00 3.50781250E+00 13 3.50976562E+00 3.51171875E+00 3.50976562E+00 CONVERGED