V.AISC 360-16 W Flex Memb F.1-1A
Verify the available flexural strength of a continuously braced wide-flange member per the AISC 360-16 code.
Details
Verify the bending capacity of a W18x50. The member is used as a 35 ft simple span. The member is continuously braced. The material is ASTM A992 (Fy = 50 ksi).
Validation
Per the User Note in F2, the W18x35 has compact flanges in major axis bending. Therefore, flange local buckling does not control. Further, as the member is continuously braced, lateral-torsional buckling does not control.
Yielding
Mn = Mp = FyZx = 50×101 = 5,050 in·k = 420.8 ft·k
LRFD
ϕbMn = 378.8 ft·k
ASD
Mn/Ωb = 252.0 ft·k
Results
| Result Type | Reference | STAAD.Pro | Difference | Comments |
|---|---|---|---|---|
| ϕbMn (ft·k) | 378.8 | 378.8 | none | |
| Mn/Ωb (ft·k) | 252.0 | 252.0 | none |
STAAD.Pro Input File
The file C:\Users\Public\Public Documents\STAAD.Pro CONNECT Edition\Samples\ Verification Models\09 Steel Design\US\AISC\AISC 360-16 W Flex Memb F.STD is typically installed with the program.
STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 06-Feb-19
END JOB INFORMATION
INPUT WIDTH 79
UNIT FEET KIP
JOINT COORDINATES
1 0 0 0; 2 35 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 W18X50
CONSTANTS
MATERIAL STEEL ALL
SUPPORTS
2 FIXED BUT FX MZ
1 FIXED BUT MZ
LOAD 1 LOADTYPE None TITLE LOAD CASE 1
MEMBER LOAD
1 UNI GY -0.45
LOAD 2 LOADTYPE None TITLE LOAD CASE 2
MEMBER LOAD
1 UNI GY -0.75
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 2016
METHOD LRFD
SGR 28 ALL
FLX 2 ALL
TRACK 2 ALL
CHECK CODE ALL
LOAD LIST 4
PARAMETER 2
CODE AISC UNIFIED 2016
METHOD ASD
SGR 28 ALL
FLX 2 ALL
TRACK 2 ALL
CHECK CODE ALL
FINISH
STAAD.Pro Output
STAAD.PRO CODE CHECKING - AISC 360-16 LRFD (V1.2) ***************************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted). ***NOTE : AISC 360-16 Design Statement for STAAD.Pro. *** AXIS CONVENTION ***: ======================== The capacity results and intermediate results in the report follow the notations and axes labels as defined in the AISC 360-16 code. The analysis results are reported in STAAD.Pro axis convention and the AISC 360:16 design results are reported in AISC 360-16 code axis convention. AISC Spec. STAAD.Pro Description ------------ ----------- ------------- X Z Axis typically parallel to the sections principal major axis. Y Y Axis typically parallel to the sections principal minor axis. Z X Longitudinal axis perpendicular to the cross section. SECTION FORCES AXIS MAPPING: - AISC Spec. STAAD.Pro Description ------------ ----------- ------------- Pz FX Axial force. Vy FY Shear force along minor axis. Vx FZ Shear force along major axis. Tz MX Torsional moment. My MY Bending moment about minor axis. Mx MZ Bending moment about major axis. *** DESIGN MESSAGES ***: ======================= 1. Section classification reported is for the cross section and loadcase that produced the worst case design ratio for flexure/compression Capacity results. 2. Results for any Capacity/Check that is not relevant for a section/loadcase based on the code clause in AISC 360-16 will not be shown in the report. 3. Bending results are reported as being �about� the relevant axis (X/Y), while the results for shear are reported as being for shear forces �along� the axis. E.g : Mx indicates bending about the X axis, while Vx indicates shear along the X axis. *** ABBREVIATIONS ***: ====================== F-T-B = Flexural-Torsional Buckling L-T-B = Lateral-Torsional Buckling F-L-B = Flange Local Buckling W-L-B = Web Local Buckling L-L-B = Leg Local Buckling C-F-Y = Compression Flange Yielding T-F-Y = Tension Flange Yielding STAAD SPACE -- PAGE NO. 7 STAAD.PRO CODE CHECKING - AISC 360-16 LRFD (V1.2) ***************************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted). - Member : 1 |-----------------------------------------------------------------------------| | Member No: 1 Profile: ST W18X50 (AISC SECTIONS)| | Status: PASS Ratio: 0.703 Loadcase: 3 | | Location: 17.50 Ref: Cl.F2.1 | | Pz: 0.000 T Vy: 0.000 Vx: 0.000 | | Tz: 0.000 My: 0.000 Mx: -266.4 | |-----------------------------------------------------------------------------| | TENSION SLENDERNESS | | Actual Slenderness Ratio : 254.294 | | Allowable Slenderness Ratio : 300.000 LOC : 0.00 | |-----------------------------------------------------------------------------| | STRENGTH CHECKS | | Critical L/C : 3 Ratio : 0.703(PASS) | | Loc : 17.50 Condition : Cl.F2.1 | |-----------------------------------------------------------------------------| | SECTION PROPERTIES (LOC: 17.50, PROPERTIES UNIT: IN ) | | Ag : 1.470E+01 Axx : 8.550E+00 Ayy : 6.390E+00 | | Ixx : 8.000E+02 Iyy : 4.010E+01 J : 1.240E+00 | | Sxx+: 8.889E+01 Sxx-: 8.889E+01 Zxx : 1.010E+02 | | Syy+: 1.069E+01 Syy-: 1.069E+01 Zyy : 1.660E+01 | | Cw : 3.044E+03 x0 : 0.000E+00 y0 : 0.000E+00 | |-----------------------------------------------------------------------------| | MATERIAL PROPERTIES | | Fyld: 7200.000 Fu: 9359.999 | |-----------------------------------------------------------------------------| | Actual Member Length: 35.000 | | Design Parameters (Rolled) | | Kx: 1.00 Ky: 1.00 NSF: 1.00 SLF: 1.00 CSP: 1.00 | |-----------------------------------------------------------------------------| | COMPRESSION CLASSIFICATION (L/C: 3 LOC: 420.00) | | λ λp λr CASE | | Flange: NonSlender 6.58 N/A 13.49 Table.B4.1a.Case1 | | Web : Slender 45.23 N/A 35.88 Table.B4.1a.Case5 | | | | FLEXURE CLASSIFICATION (L/C: 3 LOC: 420.00) | | λ λp λr CASE | | Flange: Compact 6.58 9.15 24.08 Table.B4.1b.Case10 | | Web : Compact 45.23 90.55 137.27 Table.B4.1b.Case15 | |-----------------------------------------------------------------------------| STAAD SPACE -- PAGE NO. 8 STAAD.PRO CODE CHECKING - AISC 360-16 LRFD (V1.2) ***************************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted). - Member : 1 Contd. |-----------------------------------------------------------------------------| | CHECKS FOR AXIAL TENSION | |-----------------------------------------------------------------------------| | TENSILE YIELDING | | DEMAND CAPACITY RATIO REFERENCE L/C LOC | | 0.000 661.5 0.000 Cl.D2 3 0.00 | | | | Intermediate Results : | | Nom. Ten. Yld Cap : Pn = 735.00 kip Eq.D2-1 | |-----------------------------------------------------------------------------| | TENSILE RUPTURE | | DEMAND CAPACITY RATIO REFERENCE L/C LOC | | 0.000 716.6 0.000 Cl.D2 3 0.00 | | | | Intermediate Results : | | Effective area : Ae = 0.10208 ft2 Eq.D3-1 | | Nom. Ten. Rpt Cap : Pn = 955.50 kip Eq.D2-2 | |-----------------------------------------------------------------------------| | CHECKS FOR AXIAL COMPRESSION | |-----------------------------------------------------------------------------| | FLEXURAL BUCKLING X | | DEMAND CAPACITY RATIO REFERENCE L/C LOC | | 0.000 506.3 0.000 Cl.E3 3 0.00 | | | | Intermediate Results : | | Effective Slenderness : Lcx/rx = 56.933 Cl.E2 | | Elastic Buckling Stress : Fex = 12716. kip/ft2 Eq.E3-4 | | Crit. Buckling Stress : Fcrx = 5680.7 kip/ft2 Eq.E3-2 | | Nom. Flexural Buckling : Pnx = 562.50 kip Eq.E7-1 | |-----------------------------------------------------------------------------| | FLEXURAL BUCKLING Y | | DEMAND CAPACITY RATIO REFERENCE L/C LOC | | 0.000 51.36 0.000 Cl.E3 3 0.00 | | | | Intermediate Results : | | Effective Slenderness : Lcy/ry = 254.29 Cl.E2 | | Elastic Buckling Stress : Fey = 637.37 kip/ft2 Eq.E3-4 | | Crit. Buckling Stress : Fcry = 558.97 kip/ft2 Eq.E3-3 | | Nom. Flexural Buckling : Pny = 57.061 kip Eq.E7-1 | |-----------------------------------------------------------------------------| | FLEXURAL-TORSIONAL-BUCKLING | | DEMAND CAPACITY RATIO REFERENCE L/C LOC | | 0.000 260.0 0.000 Cl.E4 3 0.00 | | | | Intermediate Results : | | Elastic F-T-B Stress : Fe = 3227.1 kip/ft2 Eq.E4-2 | | Crit. F-T-B Stress : Fcr = 2829.9 kip/ft2 Eq.E3-2 | | Nom. Flex-tor Buckling : Pn = 288.89 kip Eq.E7-1 | |-----------------------------------------------------------------------------| STAAD SPACE -- PAGE NO. 9 STAAD.PRO CODE CHECKING - AISC 360-16 LRFD (V1.2) ***************************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted). - Member : 1 Contd. |-----------------------------------------------------------------------------| | CHECKS FOR SHEAR | |-----------------------------------------------------------------------------| | SHEAR ALONG X | | DEMAND CAPACITY RATIO REFERENCE L/C LOC | | 0.000 230.8 0.000 Cl.G1 3 0.00 | | | | Intermediate Results : | | Coefficient Cv Along X : Cv = 1.0000 Eq.G2-9 | | Coefficient Kv Along X : Kv = 1.2000 Cl.G6 | | Nom. Shear Along X : Vnx = 256.50 kip Eq.G6-1 | |-----------------------------------------------------------------------------| | SHEAR ALONG Y | | DEMAND CAPACITY RATIO REFERENCE L/C LOC | | 30.45 191.7 0.159 Cl.G1 3 0.00 | | | | Intermediate Results : | | Coefficient Cv Along Y : Cv = 1.0000 - | | Coefficient Kv Along Y : Kv = 5.3400 Eq.G2-5 | | Nom. Shear Along Y : Vny = 191.70 kip Eq.G2-1 | |-----------------------------------------------------------------------------| STAAD SPACE -- PAGE NO. 10 STAAD.PRO CODE CHECKING - AISC 360-16 LRFD (V1.2) ***************************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted). - Member : 1 Contd. |-----------------------------------------------------------------------------| | CHECKS FOR BENDING | |-----------------------------------------------------------------------------| | FLEXURAL YIELDING (X) | | DEMAND CAPACITY RATIO REFERENCE L/C LOC | | -266.4 378.8 0.703 Cl.F2.1 3 17.50 | | | | Intermediate Results : | | Nom Flex Yielding Along X : Mnx = 420.83 kip-ft Eq.F2-1 | |-----------------------------------------------------------------------------| | FLEXURAL YIELDING (Y) | | DEMAND CAPACITY RATIO REFERENCE L/C LOC | | 0.000 62.25 0.000 Cl.F6.1 3 0.00 | | | | Intermediate Results : | | Nom Flex Yielding Along Y : Mny = 69.167 kip-ft Eq.F6-1 | |-----------------------------------------------------------------------------| STAAD SPACE -- PAGE NO. 11 STAAD.PRO CODE CHECKING - AISC 360-16 LRFD (V1.2) ***************************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted). - Member : 1 Contd. |-----------------------------------------------------------------------------| | CHECKS FOR AXIAL BEND INTERACTION | |-----------------------------------------------------------------------------| | COMBINED FORCES CLAUSE H1 | | RATIO CRITERIA L/C LOC | | 0.703 Eq.H1-1b 3 17.50 | | | | Intermediate Results : | | Modification Fact. for Cb : Cbf = 1.0000 Eq.H1-2 | | Axial Capacity : Pc = 661.50 kip Cl.H1.1 | | Moment Capacity : Mcx = 378.75 kip-ft Cl.H1.1 | | Moment Capacity : Mcy = 62.250 kip-ft Cl.H1.1 | |-----------------------------------------------------------------------------| 48. LOAD LIST 4 49. PARAMETER 2 50. CODE AISC UNIFIED 2016 51. METHOD ASD 52. SGR 28 ALL 53. FLX 2 ALL 54. TRACK 2 ALL 55. CHECK CODE ALL PARAMETER 2 STAAD SPACE -- PAGE NO. 12 STAAD.PRO CODE CHECKING - AISC 360-16 ASD (V1.2) **************************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted). ***NOTE : AISC 360-16 Design Statement for STAAD.Pro. *** AXIS CONVENTION ***: ======================== The capacity results and intermediate results in the report follow the notations and axes labels as defined in the AISC 360-16 code. The analysis results are reported in STAAD.Pro axis convention and the AISC 360:16 design results are reported in AISC 360-16 code axis convention. AISC Spec. STAAD.Pro Description ------------ ----------- ------------- X Z Axis typically parallel to the sections principal major axis. Y Y Axis typically parallel to the sections principal minor axis. Z X Longitudinal axis perpendicular to the cross section. SECTION FORCES AXIS MAPPING: - AISC Spec. STAAD.Pro Description ------------ ----------- ------------- Pz FX Axial force. Vy FY Shear force along minor axis. Vx FZ Shear force along major axis. Tz MX Torsional moment. My MY Bending moment about minor axis. Mx MZ Bending moment about major axis. *** DESIGN MESSAGES ***: ======================= 1. Section classification reported is for the cross section and loadcase that produced the worst case design ratio for flexure/compression Capacity results. 2. Results for any Capacity/Check that is not relevant for a section/loadcase based on the code clause in AISC 360-16 will not be shown in the report. 3. Bending results are reported as being �about� the relevant axis (X/Y), while the results for shear are reported as being for shear forces �along� the axis. E.g : Mx indicates bending about the X axis, while Vx indicates shear along the X axis. *** ABBREVIATIONS ***: ====================== F-T-B = Flexural-Torsional Buckling L-T-B = Lateral-Torsional Buckling F-L-B = Flange Local Buckling W-L-B = Web Local Buckling L-L-B = Leg Local Buckling C-F-Y = Compression Flange Yielding T-F-Y = Tension Flange Yielding STAAD SPACE -- PAGE NO. 13 STAAD.PRO CODE CHECKING - AISC 360-16 ASD (V1.2) **************************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted). - Member : 1 |-----------------------------------------------------------------------------| | Member No: 1 Profile: ST W18X50 (AISC SECTIONS)| | Status: PASS Ratio: 0.729 Loadcase: 4 | | Location: 17.50 Ref: Cl.F2.1 | | Pz: 0.000 T Vy: 0.000 Vx: 0.000 | | Tz: 0.000 My: 0.000 Mx: -183.8 | |-----------------------------------------------------------------------------| | TENSION SLENDERNESS | | Actual Slenderness Ratio : 254.294 | | Allowable Slenderness Ratio : 300.000 LOC : 0.00 | |-----------------------------------------------------------------------------| | STRENGTH CHECKS | | Critical L/C : 4 Ratio : 0.729(PASS) | | Loc : 17.50 Condition : Cl.F2.1 | |-----------------------------------------------------------------------------| | SECTION PROPERTIES (LOC: 17.50, PROPERTIES UNIT: IN ) | | Ag : 1.470E+01 Axx : 8.550E+00 Ayy : 6.390E+00 | | Ixx : 8.000E+02 Iyy : 4.010E+01 J : 1.240E+00 | | Sxx+: 8.889E+01 Sxx-: 8.889E+01 Zxx : 1.010E+02 | | Syy+: 1.069E+01 Syy-: 1.069E+01 Zyy : 1.660E+01 | | Cw : 3.044E+03 x0 : 0.000E+00 y0 : 0.000E+00 | |-----------------------------------------------------------------------------| | MATERIAL PROPERTIES | | Fyld: 7200.000 Fu: 9359.999 | |-----------------------------------------------------------------------------| | Actual Member Length: 35.000 | | Design Parameters (Rolled) | | Kx: 1.00 Ky: 1.00 NSF: 1.00 SLF: 1.00 CSP: 1.00 | |-----------------------------------------------------------------------------| | COMPRESSION CLASSIFICATION (L/C: 4 LOC: 420.00) | | λ λp λr CASE | | Flange: NonSlender 6.58 N/A 13.49 Table.B4.1a.Case1 | | Web : Slender 45.23 N/A 35.88 Table.B4.1a.Case5 | | | | FLEXURE CLASSIFICATION (L/C: 4 LOC: 420.00) | | λ λp λr CASE | | Flange: Compact 6.58 9.15 24.08 Table.B4.1b.Case10 | | Web : Compact 45.23 90.55 137.27 Table.B4.1b.Case15 | |-----------------------------------------------------------------------------| STAAD SPACE -- PAGE NO. 14 STAAD.PRO CODE CHECKING - AISC 360-16 ASD (V1.2) **************************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted). - Member : 1 Contd. |-----------------------------------------------------------------------------| | CHECKS FOR AXIAL TENSION | |-----------------------------------------------------------------------------| | TENSILE YIELDING | | DEMAND CAPACITY RATIO REFERENCE L/C LOC | | 0.000 440.1 0.000 Cl.D2 4 0.00 | | | | Intermediate Results : | | Nom. Ten. Yld Cap : Pn = 735.00 kip Eq.D2-1 | |-----------------------------------------------------------------------------| | TENSILE RUPTURE | | DEMAND CAPACITY RATIO REFERENCE L/C LOC | | 0.000 477.7 0.000 Cl.D2 4 0.00 | | | | Intermediate Results : | | Effective area : Ae = 0.10208 ft2 Eq.D3-1 | | Nom. Ten. Rpt Cap : Pn = 955.50 kip Eq.D2-2 | |-----------------------------------------------------------------------------| | CHECKS FOR AXIAL COMPRESSION | |-----------------------------------------------------------------------------| | FLEXURAL BUCKLING X | | DEMAND CAPACITY RATIO REFERENCE L/C LOC | | 0.000 336.8 0.000 Cl.E3 4 0.00 | | | | Intermediate Results : | | Effective Slenderness : Lcx/rx = 56.933 Cl.E2 | | Elastic Buckling Stress : Fex = 12716. kip/ft2 Eq.E3-4 | | Crit. Buckling Stress : Fcrx = 5680.7 kip/ft2 Eq.E3-2 | | Nom. Flexural Buckling : Pnx = 562.50 kip Eq.E7-1 | |-----------------------------------------------------------------------------| | FLEXURAL BUCKLING Y | | DEMAND CAPACITY RATIO REFERENCE L/C LOC | | 0.000 34.17 0.000 Cl.E3 4 0.00 | | | | Intermediate Results : | | Effective Slenderness : Lcy/ry = 254.29 Cl.E2 | | Elastic Buckling Stress : Fey = 637.37 kip/ft2 Eq.E3-4 | | Crit. Buckling Stress : Fcry = 558.97 kip/ft2 Eq.E3-3 | | Nom. Flexural Buckling : Pny = 57.061 kip Eq.E7-1 | |-----------------------------------------------------------------------------| | FLEXURAL-TORSIONAL-BUCKLING | | DEMAND CAPACITY RATIO REFERENCE L/C LOC | | 0.000 173.0 0.000 Cl.E4 4 0.00 | | | | Intermediate Results : | | Elastic F-T-B Stress : Fe = 3227.1 kip/ft2 Eq.E4-2 | | Crit. F-T-B Stress : Fcr = 2829.9 kip/ft2 Eq.E3-2 | | Nom. Flex-tor Buckling : Pn = 288.89 kip Eq.E7-1 | |-----------------------------------------------------------------------------| STAAD SPACE -- PAGE NO. 15 STAAD.PRO CODE CHECKING - AISC 360-16 ASD (V1.2) **************************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted). - Member : 1 Contd. |-----------------------------------------------------------------------------| | CHECKS FOR SHEAR | |-----------------------------------------------------------------------------| | SHEAR ALONG X | | DEMAND CAPACITY RATIO REFERENCE L/C LOC | | 0.000 153.6 0.000 Cl.G1 4 0.00 | | | | Intermediate Results : | | Coefficient Cv Along X : Cv = 1.0000 Eq.G2-9 | | Coefficient Kv Along X : Kv = 1.2000 Cl.G6 | | Nom. Shear Along X : Vnx = 256.50 kip Eq.G6-1 | |-----------------------------------------------------------------------------| | SHEAR ALONG Y | | DEMAND CAPACITY RATIO REFERENCE L/C LOC | | 21.00 127.8 0.164 Cl.G1 4 0.00 | | | | Intermediate Results : | | Coefficient Cv Along Y : Cv = 1.0000 - | | Coefficient Kv Along Y : Kv = 5.3400 Eq.G2-5 | | Nom. Shear Along Y : Vny = 191.70 kip Eq.G2-1 | |-----------------------------------------------------------------------------| STAAD SPACE -- PAGE NO. 16 STAAD.PRO CODE CHECKING - AISC 360-16 ASD (V1.2) **************************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted). - Member : 1 Contd. |-----------------------------------------------------------------------------| | CHECKS FOR BENDING | |-----------------------------------------------------------------------------| | FLEXURAL YIELDING (X) | | DEMAND CAPACITY RATIO REFERENCE L/C LOC | | -183.8 252.0 0.729 Cl.F2.1 4 17.50 | | | | Intermediate Results : | | Nom Flex Yielding Along X : Mnx = 420.83 kip-ft Eq.F2-1 | |-----------------------------------------------------------------------------| | FLEXURAL YIELDING (Y) | | DEMAND CAPACITY RATIO REFERENCE L/C LOC | | 0.000 41.42 0.000 Cl.F6.1 4 0.00 | | | | Intermediate Results : | | Nom Flex Yielding Along Y : Mny = 69.167 kip-ft Eq.F6-1 | |-----------------------------------------------------------------------------| STAAD SPACE -- PAGE NO. 17 STAAD.PRO CODE CHECKING - AISC 360-16 ASD (V1.2) **************************************************** ALL UNITS ARE - KIP FEET (UNLESS OTHERWISE Noted). - Member : 1 Contd. |-----------------------------------------------------------------------------| | CHECKS FOR AXIAL BEND INTERACTION | |-----------------------------------------------------------------------------| | COMBINED FORCES CLAUSE H1 | | RATIO CRITERIA L/C LOC | | 0.729 Eq.H1-1b 4 17.50 | | | | Intermediate Results : | | Modification Fact. for Cb : Cbf = 1.0000 Eq.H1-2 | | Axial Capacity : Pc = 440.12 kip Cl.H1.1 | | Moment Capacity : Mcx = 252.00 kip-ft Cl.H1.1 | | Moment Capacity : Mcy = 41.417 kip-ft Cl.H1.1 | |-----------------------------------------------------------------------------|