V. AISC 360-10 W Local Buckling F.3
Verify the leg local buckling flexural strength of a non-compact wide flange section per the LRFD and ASD methods of the AISC 360-10 code.
References
- American Institute of Steel Construction. 2010 Steel Construction Manual. Fourteenth Edition. AISC: Chicago, IL.
-
American Institute of Steel Construction. 2011. Design Examples, Version 14.0. AISC:Chicago, IL. Example F.3A and F.3B, pp. F22 - F25
Note: This reference is freely available for download from the AISC website at https://www.aisc.org/globalassets/aisc/university-programs/teaching-aids/first-semester-design-examples.pdf
Details
From reference (2):
Select an ASTM A992 W-shape beam with a simple span of 40 ft. The nominal loads are a uniform dead load of 0.05 kip/ft and two equal 18 kip concentrated live loads acting at the third points of the beam. The beam is continuously braced.
Results
Result Type | Reference | STAAD.Pro | Difference | Comments |
---|---|---|---|---|
ϕbMn (ft·k) [LRFD] | 398 | 398 | none | |
Mn/Ωb (ft·k) [ASD] | 265 | 265 | none |
STAAD.Pro Input
The file C:\Users\Public\Public Documents\STAAD.Pro 2023\Samples \Verification Models\09 Steel Design\US\AISC\AISC 360-10 W Local Buckling F.3.STD is typically installed with the program.
STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 14-Feb-19
END JOB INFORMATION
INPUT WIDTH 79
UNIT FEET KIP
JOINT COORDINATES
1 0 0 0; 2 40 0 0;
MEMBER INCIDENCES
1 1 2;
DEFINE MATERIAL START
ISOTROPIC STEEL
E 4.176e+06
POISSON 0.3
DENSITY 0.489024
ALPHA 6.5e-06
DAMP 0.03
TYPE STEEL
STRENGTH RY 1.5 RT 1.2
END DEFINE MATERIAL
MEMBER PROPERTY AMERICAN
1 TABLE ST W21X48
CONSTANTS
MATERIAL STEEL ALL
SUPPORTS
1 FIXED BUT MZ
2 FIXED BUT FX MZ
LOAD 1 LOADTYPE None TITLE LOAD CASE 1
MEMBER LOAD
1 UNI GY -0.05
LOAD 2 LOADTYPE None TITLE LOAD CASE 2
MEMBER LOAD
1 CON GY -18 13.333
1 CON GY -18 26.667
LOAD COMB 3 COMBINATION LOAD CASE 3
1 1.2 2 1.6
LOAD COMB 4 COMBINATION LOAD CASE 4
1 1.0 2 1.0
PERFORM ANALYSIS
PRINT ANALYSIS RESULTS
LOAD LIST 3
PARAMETER 1
CODE AISC UNIFIED 2010
FU 9360 ALL
FYLD 7200 ALL
FLX 2 ALL
METHOD LRFD
TRACK 2 ALL
CHECK CODE ALL
LOAD LIST 4
PARAMETER 2
CODE AISC UNIFIED 2010
FU 9360 ALL
FYLD 7200 ALL
FLX 2 ALL
METHOD ASD
TRACK 2 ALL
CHECK CODE ALL
FINISH
STAAD.Pro Output
STAAD.PRO CODE CHECKING - (AISC-360-10-LRFD) v1.4a ******************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted) MEMBER TABLE RESULT/ CRITICAL COND/ RATIO/ LOADING/ FX MY MZ LOCATION ======================================================================= * 1 ST W21X48 (AISC SECTIONS) FAIL Eq. H1-1b 6.470 3 0.00 0.00 -395.99 20.00 |-----------------------------------------------------------------------| | SLENDERNESS | | Actual Slenderness Ratio : 289.731 L/C : 3 | | Allowable Slenderness Ratio : 300.000 LOC : 20.00 | |-----------------------------------------------------------------------| | STRENGTH CHECKS | | Critical L/C : 3 Ratio : 6.470(FAIL) | | Loc : 20.00 Condition : Eq. H1-1b | |-----------------------------------------------------------------------| | DESIGN FORCES | | Fx: 0.000E+00( ) Fy: 0.000E+00 Fz: 0.000E+00 | | Mx: 0.000E+00 My: 0.000E+00 Mz: -3.960E+02 | |-----------------------------------------------------------------------| | SECTION PROPERTIES (UNIT: INCH) | | Azz: 7.000E+00 Ayy: 7.210E+00 Cw: 3.936E+03 | | Szz: 9.311E+01 Syy: 9.509E+00 | | Izz: 9.590E+02 Iyy: 3.870E+01 Ix: 8.030E-01 | |-----------------------------------------------------------------------| | MATERIAL PROPERTIES | | Fyld: 7199.999 Fu: 9359.999 | |-----------------------------------------------------------------------| | Actual Member Length: 40.000 | | Design Parameters | | Kz: 1.00 Ky: 1.00 NSF: 1.00 SLF: 1.00 CSP: 12.00 | |-----------------------------------------------------------------------| | SECTION CLASS UNSTIFFENED / λ λp λr CASE | | STIFFENED | | Compression : Non-Slender 9.47 N/A 13.49 T.B4.1(a)-1 | | Slender 53.54 N/A 35.88 T.B4.1(a)-5 | | Flexure : Non-Compact 9.47 9.15 24.08 T.B4.1(b)-10 | | Compact 53.54 90.55 137.27 T.B4.1(b)-15 | STAAD SPACE -- PAGE NO. 7 STAAD.PRO CODE CHECKING - (AISC-360-10-LRFD) v1.4a ******************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted) |-----------------------------------------------------------------------| | CHECK FOR AXIAL TENSION | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | Yield -0.00E+00 6.35E+02 0.000 Eq. D2-1 3 0.00 | | Rupture -0.00E+00 6.87E+02 0.000 Eq. D2-2 3 0.00 | |-----------------------------------------------------------------------| | CHECK FOR AXIAL COMPRESSION | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | Maj Buck 0.00E+00 4.61E+02 0.000 Eq. E7-1 3 0.00 | | Min Buck 0.00E+00 3.79E+01 0.000 Eq. E7-1 3 0.00 | | Flexural | | Tor Buck 0.00E+00 1.54E+02 0.000 Eq. E7-1 3 0.00 | | Intermediate | | Results Eff Area KL/r Fcr Fe Pn | | Maj Buck 8.92E-02 58.20 5.23E+03 1.22E+04 5.12E+02 | | Min Buck 9.79E-02 289.73 4.31E+02 4.91E+02 4.22E+01 | | Flexural Ag Fcr Pn | | Tor Buck 9.79E-02 1.75E+03 1.72E+02 | |-----------------------------------------------------------------------| | CHECK FOR SHEAR | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | Local-Z -0.00E+00 1.89E+02 0.000 Eq. G2-1 3 0.00 | | Local-Y 3.00E+01 2.16E+02 0.139 Eq. G2-1 3 0.00 | | Intermediate | | Results Aw Cv Kv h/tw Vn | | Local-Z 4.86E-02 1.00 1.20 9.47 2.10E+02 | | Local-Y 5.01E-02 1.00 0.00 53.54 2.16E+02 | |-----------------------------------------------------------------------| | CHECK FOR BENDING-YIELDING | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | Major 3.96E+02 4.01E+02 0.987 Eq. F2-1 3 20.00 | | Minor 0.00E+00 5.59E+01 0.000 Eq. F6-1 3 0.00 | | Intermediate Mn My | | Major 4.46E+02 0.00E+00 | | Minor 6.21E+01 0.00E+00 | |-----------------------------------------------------------------------| | CHECK FOR BENDING-LATERAL TORSIONAL BUCKLING | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | Major 3.96E+02 6.12E+01 6.470 Eq. F2-3 3 20.00 | | Intermediate Mn Me Cb Lp Lr Lb | | Major 6.80E+01 0.00E+00 1.00 5.85 16.53 40.00 | STAAD SPACE -- PAGE NO. 8 STAAD.PRO CODE CHECKING - (AISC-360-10-LRFD) v1.4a ******************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted) |-----------------------------------------------------------------------| | CHECK FOR BENDING-FLANGE LOCAL BUCKLING | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | Major 3.96E+02 3.98E+02 0.995 Eq. F3-1 3 20.00 | | Minor 0.00E+00 5.52E+01 0.000 Eq. F6-2 3 0.00 | | Intermediate Mn Fcr | | Major 4.42E+02 0.00E+00 | | Minor 6.14E+01 0.00E+00 | |-----------------------------------------------------------------------| | CHECK FOR FLEXURE TENS/COMP INTERACTION | | RATIO CRITERIA L/C LOC | | Flexure Comp 6.470 Eq. H1-1b 3 20.00 | | Flexure Tens 6.470 Eq. H1-1b 3 20.00 | | Intermediate Mcx Mrx Pc | | Mcy Mry Pr | | Flexure Comp 6.12E+01 3.96E+02 3.79E+01 | | 5.52E+01 0.00E+00 0.00E+00 | | Flexure Tens 6.12E+01 3.96E+02 6.35E+02 | | 5.52E+01 0.00E+00 -0.00E+00 | |-----------------------------------------------------------------------| 50. LOAD LIST 4 51. PARAMETER 2 52. CODE AISC UNIFIED 2010 53. FU 9360 ALL 54. FYLD 7200 ALL 55. FLX 2 ALL 56. METHOD ASD 57. TRACK 2 ALL 58. CHECK CODE ALL STEEL DESIGN STAAD SPACE -- PAGE NO. 9 STAAD.PRO CODE CHECKING - ( AISC-360-10-ASD) v1.4a ******************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted) MEMBER TABLE RESULT/ CRITICAL COND/ RATIO/ LOADING/ FX MY MZ LOCATION ======================================================================= * 1 ST W21X48 (AISC SECTIONS) FAIL Eq. H1-1b 6.139 4 0.00 0.00 -249.99 20.00 |-----------------------------------------------------------------------| | SLENDERNESS | | Actual Slenderness Ratio : 289.731 L/C : 4 | | Allowable Slenderness Ratio : 300.000 LOC : 20.00 | |-----------------------------------------------------------------------| | STRENGTH CHECKS | | Critical L/C : 4 Ratio : 6.139(FAIL) | | Loc : 20.00 Condition : Eq. H1-1b | |-----------------------------------------------------------------------| | DESIGN FORCES | | Fx: 0.000E+00( ) Fy: 0.000E+00 Fz: 0.000E+00 | | Mx: 0.000E+00 My: 0.000E+00 Mz: -2.500E+02 | |-----------------------------------------------------------------------| | SECTION PROPERTIES (UNIT: INCH) | | Azz: 7.000E+00 Ayy: 7.210E+00 Cw: 3.936E+03 | | Szz: 9.311E+01 Syy: 9.509E+00 | | Izz: 9.590E+02 Iyy: 3.870E+01 Ix: 8.030E-01 | |-----------------------------------------------------------------------| | MATERIAL PROPERTIES | | Fyld: 7199.999 Fu: 9359.999 | |-----------------------------------------------------------------------| | Actual Member Length: 40.000 | | Design Parameters | | Kz: 1.00 Ky: 1.00 NSF: 1.00 SLF: 1.00 CSP: 12.00 | |-----------------------------------------------------------------------| | SECTION CLASS UNSTIFFENED / λ λp λr CASE | | STIFFENED | | Compression : Non-Slender 9.47 N/A 13.49 T.B4.1(a)-1 | | Slender 53.54 N/A 35.88 T.B4.1(a)-5 | | Flexure : Non-Compact 9.47 9.15 24.08 T.B4.1(b)-10 | | Compact 53.54 90.55 137.27 T.B4.1(b)-15 | STAAD SPACE -- PAGE NO. 10 STAAD.PRO CODE CHECKING - ( AISC-360-10-ASD) v1.4a ******************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted) |-----------------------------------------------------------------------| | CHECK FOR AXIAL TENSION | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | Yield -0.00E+00 4.22E+02 0.000 Eq. D2-1 4 0.00 | | Rupture -0.00E+00 4.58E+02 0.000 Eq. D2-2 4 0.00 | |-----------------------------------------------------------------------| | CHECK FOR AXIAL COMPRESSION | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | Maj Buck 0.00E+00 3.07E+02 0.000 Eq. E7-1 4 0.00 | | Min Buck 0.00E+00 2.52E+01 0.000 Eq. E7-1 4 0.00 | | Flexural | | Tor Buck 0.00E+00 1.03E+02 0.000 Eq. E7-1 4 0.00 | | Intermediate | | Results Eff Area KL/r Fcr Fe Pn | | Maj Buck 8.92E-02 58.20 5.23E+03 1.22E+04 5.12E+02 | | Min Buck 9.79E-02 289.73 4.31E+02 4.91E+02 4.22E+01 | | Flexural Ag Fcr Pn | | Tor Buck 9.79E-02 1.75E+03 1.72E+02 | |-----------------------------------------------------------------------| | CHECK FOR SHEAR | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | Local-Z -0.00E+00 1.26E+02 0.000 Eq. G2-1 4 0.00 | | Local-Y 1.90E+01 1.44E+02 0.132 Eq. G2-1 4 0.00 | | Intermediate | | Results Aw Cv Kv h/tw Vn | | Local-Z 4.86E-02 1.00 1.20 9.47 2.10E+02 | | Local-Y 5.01E-02 1.00 0.00 53.54 2.16E+02 | |-----------------------------------------------------------------------| | CHECK FOR BENDING-YIELDING | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | Major 2.50E+02 2.67E+02 0.936 Eq. F2-1 4 20.00 | | Minor 0.00E+00 3.72E+01 0.000 Eq. F6-1 4 0.00 | | Intermediate Mn My | | Major 4.46E+02 0.00E+00 | | Minor 6.21E+01 0.00E+00 | |-----------------------------------------------------------------------| | CHECK FOR BENDING-LATERAL TORSIONAL BUCKLING | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | Major 2.50E+02 4.07E+01 6.139 Eq. F2-3 4 20.00 | | Intermediate Mn Me Cb Lp Lr Lb | | Major 6.80E+01 0.00E+00 1.00 5.85 16.53 40.00 | STAAD SPACE -- PAGE NO. 11 STAAD.PRO CODE CHECKING - ( AISC-360-10-ASD) v1.4a ******************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted) |-----------------------------------------------------------------------| | CHECK FOR BENDING-FLANGE LOCAL BUCKLING | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | Major 2.50E+02 2.65E+02 0.944 Eq. F3-1 4 20.00 | | Minor 0.00E+00 3.67E+01 0.000 Eq. F6-2 4 0.00 | | Intermediate Mn Fcr | | Major 4.42E+02 0.00E+00 | | Minor 6.14E+01 0.00E+00 | |-----------------------------------------------------------------------| | CHECK FOR FLEXURE TENS/COMP INTERACTION | | RATIO CRITERIA L/C LOC | | Flexure Comp 6.139 Eq. H1-1b 4 20.00 | | Flexure Tens 6.139 Eq. H1-1b 4 20.00 | | Intermediate Mcx Mrx Pc | | Mcy Mry Pr | | Flexure Comp 4.07E+01 2.50E+02 2.52E+01 | | 3.67E+01 0.00E+00 0.00E+00 | | Flexure Tens 4.07E+01 2.50E+02 4.22E+02 | | 3.67E+01 0.00E+00 -0.00E+00 | |-----------------------------------------------------------------------|