V. AISC 360-10 HSST Compact Flange F.6
Verify the available flexural strength of a square HSS flexural member with compact flanges per the AISC 360-10 code.
Details
From reference (2):
Select a square ASTM A500 Grade B HSS beam to span 7.5 ft. The loads are a uniform dead load of 0.145 kip/ft and a uniform live load of 0.435 kip/ft. Limit the live load deflection to L/240. The beam is continuously braced.
Validation
Ultimate moment:
Service moment:
Try a HSS 3 1/2×3 1/2×1/8, which has a plastic section modulus, Zx = 1.93 in3.
The yield strength, Fy = 46 ksi
Flange compactness: λ = b/t = 27.2
Determine the compact flange ratio limit from Table B4.1b: (Compact)
The available flexural strength:
LRFD:
ASD:
Results
| Result Type | Reference | STAAD.Pro | Difference | Comments |
|---|---|---|---|---|
| ϕbMn (ft·k) [LRFD] | 6.66* | 6.66 | none | |
| Mn/Ωb (ft·k) [ASD] | 4.43* | 4.43 | none |
* The reference gives ϕbMn = 6.67 ft·k and Mn/Ωb = 4.44, respectively. The differences are due to either rounding differences.
STAAD.Pro Input
The file C:\Users\Public\Public Documents\STAAD.Pro CONNECT Edition\Samples\ Verification Models\09 Steel Design\US\AISC\AISC 360-10 HSST Compact Flange F.STD is typically installed with the program.
STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 18-Feb-19
END JOB INFORMATION
INPUT WIDTH 79
UNIT FEET KIP
JOINT COORDINATES
1 0 0 0; 2 7.5 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 HSST3.5X3.5X0.125
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 -0.145
LOAD 2 LOADTYPE None TITLE LOAD CASE 2
MEMBER LOAD
1 UNI GY -0.435
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
LOAD LIST 3
PARAMETER 1
CODE AISC UNIFIED 2010
FU 8352 ALL
FYLD 6624 ALL
FLX 2 ALL
METHOD LRFD
TRACK 2 ALL
CHECK CODE ALL
LOAD LIST 4
PARAMETER 2
CODE AISC UNIFIED 2010
FU 8352 ALL
FYLD 6624 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 HSST3.5X3.5X0.125 (AISC SECTIONS) PASS Eq. H1-1b 0.919 3 0.00 0.00 -6.12 3.75 |-----------------------------------------------------------------------| | SLENDERNESS | | Actual Slenderness Ratio : 65.585 L/C : 3 | | Allowable Slenderness Ratio : 300.000 LOC : 3.75 | |-----------------------------------------------------------------------| | STRENGTH CHECKS | | Critical L/C : 3 Ratio : 0.919(PASS) | | Loc : 3.75 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: -6.117E+00 | |-----------------------------------------------------------------------| | SECTION PROPERTIES (UNIT: INCH) | | Azz: 7.313E-01 Ayy: 7.313E-01 Cw: 0.000E+00 | | Szz: 1.657E+00 Syy: 1.657E+00 | | Izz: 2.900E+00 Iyy: 2.900E+00 Ix: 4.580E+00 | |-----------------------------------------------------------------------| | MATERIAL PROPERTIES | | Fyld: 6623.999 Fu: 8351.999 | |-----------------------------------------------------------------------| | Actual Member Length: 7.500 | | 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 0.00 N/A 0.00 N/A | | Non-Slender 27.17 N/A 35.15 T.B4.1(a)-6 | | Flexure : Compact 27.17 28.12 35.15 T.B4.1(b)-17 | | Compact 27.17 60.76 143.12 T.B4.1(b)-19 | STAAD SPACE -- PAGE NO. 4 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 6.38E+01 0.000 Eq. D2-1 3 0.00 | | Rupture 0.00E+00 6.70E+01 0.000 Eq. D2-2 3 0.00 | |-----------------------------------------------------------------------| | CHECK FOR AXIAL COMPRESSION | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | Maj Buck 0.00E+00 4.77E+01 0.000 Eq. E3-1 3 0.00 | | Min Buck 0.00E+00 4.77E+01 0.000 Eq. E3-1 3 0.00 | | Intermediate | | Results Eff Area KL/r Fcr Fe Pn | | Maj Buck 1.07E-02 65.58 4.96E+03 9.58E+03 5.30E+01 | | Min Buck 1.07E-02 65.58 4.96E+03 9.58E+03 5.30E+01 | |-----------------------------------------------------------------------| | CHECK FOR SHEAR | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | Local-Z 0.00E+00 1.82E+01 0.000 Eq. G2-1 3 0.00 | | Local-Y -3.26E+00 1.82E+01 0.180 Eq. G2-1 3 7.50 | | Intermediate | | Results Aw Cv Kv h/tw Vn | | Local-Z 5.08E-03 1.00 5.00 27.17 2.02E+01 | | Local-Y 5.08E-03 1.00 5.00 27.17 2.02E+01 | |-----------------------------------------------------------------------| | CHECK FOR TORSION | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | 0.00E+00 5.49E+00 0.000 Eq. H3-1 3 0.00 | | Intermediate Fcr Tn | | 3.97E+03 6.10E+00 | |-----------------------------------------------------------------------| | CHECK FOR BENDING-YIELDING | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | Major 6.12E+00 6.66E+00 0.919 Eq. F7-1 3 3.75 | | Minor 0.00E+00 6.66E+00 0.000 Eq. F7-1 3 0.00 | | Intermediate Mn My | | Major 7.40E+00 0.00E+00 | | Minor 7.40E+00 0.00E+00 | STAAD SPACE -- PAGE NO. 5 STAAD.PRO CODE CHECKING - (AISC-360-10-LRFD) v1.4a ******************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted) |-----------------------------------------------------------------------| | CHECK FOR FLEXURE TENS/COMP INTERACTION | | RATIO CRITERIA L/C LOC | | Flexure Comp 0.919 Eq. H1-1b 3 3.75 | | Flexure Tens 0.919 Eq. H1-1b 3 3.75 | | Intermediate Mcx Mrx Pc | | Mcy Mry Pr | | Flexure Comp 6.66E+00 6.12E+00 4.77E+01 | | 6.66E+00 0.00E+00 0.00E+00 | | Flexure Tens 6.66E+00 6.12E+00 6.38E+01 | | 6.66E+00 0.00E+00 0.00E+00 | |-----------------------------------------------------------------------| 48. LOAD LIST 4 49. PARAMETER 2 50. CODE AISC UNIFIED 2010 51. FU 8352 ALL 52. FYLD 6624 ALL 53. FLX 2 ALL 54. METHOD ASD 55. TRACK 2 ALL 56. CHECK CODE ALL STEEL DESIGN WARNING: For member# 1 the profile has been selected from HSS Rect/Round (non A1085)/Pipe tables of AISC database. Weld type is considered to be Elect-resist-weld. Thickness is already reduced from the table. Further reductions will not be done. STAAD SPACE -- PAGE NO. 6 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 HSST3.5X3.5X0.125 (AISC SECTIONS) PASS Eq. H1-1b 0.921 4 0.00 0.00 -4.08 3.75 |-----------------------------------------------------------------------| | SLENDERNESS | | Actual Slenderness Ratio : 65.585 L/C : 4 | | Allowable Slenderness Ratio : 300.000 LOC : 3.75 | |-----------------------------------------------------------------------| | STRENGTH CHECKS | | Critical L/C : 4 Ratio : 0.921(PASS) | | Loc : 3.75 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: -4.078E+00 | |-----------------------------------------------------------------------| | SECTION PROPERTIES (UNIT: INCH) | | Azz: 7.313E-01 Ayy: 7.313E-01 Cw: 0.000E+00 | | Szz: 1.657E+00 Syy: 1.657E+00 | | Izz: 2.900E+00 Iyy: 2.900E+00 Ix: 4.580E+00 | |-----------------------------------------------------------------------| | MATERIAL PROPERTIES | | Fyld: 6623.999 Fu: 8351.999 | |-----------------------------------------------------------------------| | Actual Member Length: 7.500 | | 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 0.00 N/A 0.00 N/A | | Non-Slender 27.17 N/A 35.15 T.B4.1(a)-6 | | Flexure : Compact 27.17 28.12 35.15 T.B4.1(b)-17 | | Compact 27.17 60.76 143.12 T.B4.1(b)-19 | STAAD SPACE -- PAGE NO. 7 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 4.24E+01 0.000 Eq. D2-1 4 0.00 | | Rupture 0.00E+00 4.47E+01 0.000 Eq. D2-2 4 0.00 | |-----------------------------------------------------------------------| | CHECK FOR AXIAL COMPRESSION | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | Maj Buck 0.00E+00 3.18E+01 0.000 Eq. E3-1 4 0.00 | | Min Buck 0.00E+00 3.18E+01 0.000 Eq. E3-1 4 0.00 | | Intermediate | | Results Eff Area KL/r Fcr Fe Pn | | Maj Buck 1.07E-02 65.58 4.96E+03 9.58E+03 5.30E+01 | | Min Buck 1.07E-02 65.58 4.96E+03 9.58E+03 5.30E+01 | |-----------------------------------------------------------------------| | CHECK FOR SHEAR | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | Local-Z 0.00E+00 1.21E+01 0.000 Eq. G2-1 4 0.00 | | Local-Y -2.17E+00 1.21E+01 0.180 Eq. G2-1 4 7.50 | | Intermediate | | Results Aw Cv Kv h/tw Vn | | Local-Z 5.08E-03 1.00 5.00 27.17 2.02E+01 | | Local-Y 5.08E-03 1.00 5.00 27.17 2.02E+01 | |-----------------------------------------------------------------------| | CHECK FOR TORSION | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | 0.00E+00 3.65E+00 0.000 Eq. H3-1 4 0.00 | | Intermediate Fcr Tn | | 3.97E+03 6.10E+00 | |-----------------------------------------------------------------------| | CHECK FOR BENDING-YIELDING | | | | FORCE CAPACITY RATIO CRITERIA L/C LOC | | Major 4.08E+00 4.43E+00 0.921 Eq. F7-1 4 3.75 | | Minor 0.00E+00 4.43E+00 0.000 Eq. F7-1 4 0.00 | | Intermediate Mn My | | Major 7.40E+00 0.00E+00 | | Minor 7.40E+00 0.00E+00 | STAAD SPACE -- PAGE NO. 8 STAAD.PRO CODE CHECKING - ( AISC-360-10-ASD) v1.4a ******************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted) |-----------------------------------------------------------------------| | CHECK FOR FLEXURE TENS/COMP INTERACTION | | RATIO CRITERIA L/C LOC | | Flexure Comp 0.921 Eq. H1-1b 4 3.75 | | Flexure Tens 0.921 Eq. H1-1b 4 3.75 | | Intermediate Mcx Mrx Pc | | Mcy Mry Pr | | Flexure Comp 4.43E+00 4.08E+00 3.18E+01 | | 4.43E+00 0.00E+00 0.00E+00 | | Flexure Tens 4.43E+00 4.08E+00 4.24E+01 | | 4.43E+00 0.00E+00 0.00E+00 | |-----------------------------------------------------------------------|