V. AISC 360-10 Double L E.5
Reference
American Institute of Steel Construction. 2011. Design Examples, Version 14.0. AISC:Chicago, IL. Example E5, pp. E-26 - E-30.
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
Problem
From the reference:
Verify the strength of a 2L 4×3-1/2×3/8 LLBB (3/8-in. separation) strut, ASTM A36, with a length of 8 ft and pinned ends carrying an axial dead load of 20 kips and live load of 60 kips.
Refer to the reference for calculations.
Comparison
Result Type | Reference | STAAD.Pro | Difference | Comments |
---|---|---|---|---|
ϕcPn (kips) [LRFD] | 128 | 127 | negligible | |
Pn/Ωc (kips) [ASD] | 85.0 | 84.6 | negligible |
Note:
STAAD.Pro does not perform design per Section E6 of the specification. It is assumed that sufficient intermediate connectors of an appropriate type are present. It is left to the engineer to verify the intermediate connector design.
STAAD Input
The file C:\Users\Public\Public Documents\STAAD.Pro 2024\Samples Verification Models\09 Steel Design\US\AISC\360-2010\AISC 360-10 - E.STD is typically installed with the program.
Tip: You can copy and paste this content directly into a .std file to run in STAAD.Pro.
STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 5-Dec-12
END JOB INFORMATION
INPUT WIDTH 79
UNIT FEET KIP
JOINT COORDINATES
1 0 8 0; 2 0 0 0;
MEMBER INCIDENCES
1 1 2;
MEMBER PROPERTY AMERICAN
1 TABLE LD L40356 SP 0.0625
UNIT INCHES KIP
DEFINE MATERIAL START
ISOTROPIC MATERIAL1
E 29000
POISSON 0.3
ISOTROPIC STEEL
E 29000
POISSON 0.3
DENSITY 0.000283
ALPHA 6e-06
DAMP 0.03
TYPE STEEL
STRENGTH FY 36 FU 58 RY 1.5 RT 1.2
END DEFINE MATERIAL
UNIT FEET KIP
CONSTANTS
MATERIAL STEEL ALL
SUPPORTS
2 FIXED
LOAD 1 LOADTYPE None TITLE LOAD CASE 1
JOINT LOAD
1 FY -20
LOAD 2 LOADTYPE None TITLE LOAD CASE 2
JOINT LOAD
1 FY -60
LOAD COMB 3 ULTIMATE LOADS
1 1.2 2 1.6
LOAD COMB 4 SERVICE LOADS
1 1.0 2 1.0
PERFORM ANALYSIS
UNIT INCHES KIP
LOAD LIST 3
PARAMETER 1
CODE AISC UNIFIED 2010
METHOD LRFD
FYLD 36 ALL
FU 58 ALL
LX 56 ALL
TRACK 2 ALL
CHECK CODE ALL
LOAD LIST 4
PARAMETER 2
CODE AISC UNIFIED 2010
METHOD ASD
FYLD 36 ALL
FU 58 ALL
LX 56 ALL
TRACK 2 ALL
CHECK CODE ALL
FINISH
STAAD Output
STAAD.PRO CODE CHECKING - (AISC-360-10-LRFD) v1.4a
********************************************
ALL UNITS ARE - KIP INCH (UNLESS OTHERWISE Noted)
MEMBER TABLE RESULT/ CRITICAL COND/ RATIO/ LOADING/
FX MY MZ LOCATION
=======================================================================
1 LD L40356 (AISC SECTIONS)
PASS Eq. H2-1 0.943 3
120.00 C 0.00 0.00 0.00
|-----------------------------------------------------------------------|
| SLENDERNESS |
| Actual Slenderness Ratio : 76.914 L/C : 3 |
| Allowable Slenderness Ratio : 200.000 LOC : 0.00 |
|-----------------------------------------------------------------------|
| STRENGTH CHECKS |
| Critical L/C : 3 Ratio : 0.943(PASS) |
| Loc : 0.00 Condition : Eq. H2-1 |
|-----------------------------------------------------------------------|
| DESIGN FORCES |
| Fx: 1.200E+02(C ) Fy: 0.000E+00 Fz: 0.000E+00 |
| Mx: 0.000E+00 My: 0.000E+00 Mz: 0.000E+00 |
|-----------------------------------------------------------------------|
| SECTION PROPERTIES (UNIT: INCH) |
| Azz: 2.625E+00 Ayy: 1.500E+00 Cw: 0.000E+00 |
| Szz: 0.000E+00 Syy: 0.000E+00 |
| Izz: 8.350E+00 Iyy: 1.541E+01 Ix: 2.512E-01 |
|-----------------------------------------------------------------------|
| MATERIAL PROPERTIES |
| Fyld: 36.000 Fu: 58.000 |
|-----------------------------------------------------------------------|
| Actual Member Length: 96.000 |
| 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 10.67 N/A 12.77 T.B4.1(a)-3 |
| N/A N/A N/A N/A N/A |
| Flexure : Compact 9.33 15.33 25.83 T.B4.1(b)-12 |
| N/A N/A N/A N/A N/A |
STAAD SPACE -- PAGE NO. 4
STAAD.PRO CODE CHECKING - (AISC-360-10-LRFD) v1.4a
********************************************
ALL UNITS ARE - KIP INCH (UNLESS OTHERWISE Noted)
|-----------------------------------------------------------------------|
| CHECK FOR AXIAL TENSION |
| |
| FORCE CAPACITY RATIO CRITERIA L/C LOC |
| Yield 0.00E+00 1.74E+02 0.000 Eq. D2-1 3 0.00 |
| Rupture 0.00E+00 2.33E+02 0.000 Eq. D2-2 3 0.00 |
|-----------------------------------------------------------------------|
| CHECK FOR AXIAL COMPRESSION |
| |
| FORCE CAPACITY RATIO CRITERIA L/C LOC |
| Maj Buck 1.20E+02 1.27E+02 0.943 Eq. E3-1 3 0.00 |
| Min Buck 1.20E+02 1.47E+02 0.818 Eq. E3-1 3 0.00 |
| Flexural |
| Tor Buck 1.20E+02 1.36E+02 0.882 Eq. E4-1 3 0.00 |
| Intermediate |
| Results Eff Area KL/r Fcr Fe Pn |
| Maj Buck 5.36E+00 76.91 2.64E+01 4.84E+01 1.41E+02 |
| Min Buck 5.36E+00 56.61 3.04E+01 8.93E+01 1.63E+02 |
| Flexural Ag Fcr Pn |
| Tor Buck 0.00E+00 2.82E+01 1.51E+02 |
|-----------------------------------------------------------------------|
| CHECK FOR SHEAR |
| |
| FORCE CAPACITY RATIO CRITERIA L/C LOC |
| Local-Z 0.00E+00 5.10E+01 0.000 Eq. G2-1 3 0.00 |
| Local-Y 0.00E+00 2.92E+01 0.000 Eq. G2-1 3 0.00 |
| Intermediate |
| Results Aw Cv Kv h/tw Vn |
| Local-Z 2.62E+00 1.00 1.20 9.33 5.67E+01 |
| Local-Y 1.50E+00 1.00 1.20 10.67 3.24E+01 |
|-----------------------------------------------------------------------|
| CHECK FOR BENDING-YIELDING |
| |
| FORCE CAPACITY RATIO CRITERIA L/C LOC |
| Major 0.00E+00 1.55E+02 0.000 Eq. F9-1 3 0.00 |
| Minor 0.00E+00 2.06E+02 0.000 Eq. F6-1 3 0.00 |
| Intermediate Mn My |
| Major 1.72E+02 0.00E+00 |
| Minor 2.29E+02 0.00E+00 |
|-----------------------------------------------------------------------|
| CHECK FOR BENDING-LATERAL TORSIONAL BUCKLING |
| |
| FORCE CAPACITY RATIO CRITERIA L/C LOC |
| Major 0.00E+00 2.09E+03 0.000 Eq. F9-4 3 0.00 |
| Intermediate Mn Me Cb Lp Lr Lb |
| Major 2.32E+03 0.00E+00 1.00 0.00 0.00 96.00 |
STAAD SPACE -- PAGE NO. 5
STAAD.PRO CODE CHECKING - (AISC-360-10-LRFD) v1.4a
********************************************
ALL UNITS ARE - KIP INCH (UNLESS OTHERWISE Noted)
|-----------------------------------------------------------------------|
| CHECK FOR FLEXURE TENS/COMP INTERACTION |
| RATIO CRITERIA L/C LOC |
| Flexure Comp 0.943 Eq. H2-1 3 0.00 |
| Flexure Tens 0.000 Eq. H2-1 3 0.00 |
| Intermediate frbw / frbz / fra / |
| Fcbw Fcbz Fca |
| Flexure Comp 0.00E+00 0.00E+00 2.24E+01 |
| 5.18E+01 5.18E+01 2.37E+01 |
| Flexure Tens 0.00E+00 0.00E+00 0.00E+00 |
| 2.23E+01 5.18E+01 3.24E+01 |
|-----------------------------------------------------------------------|
53. LOAD LIST 4
54. PARAMETER 2
55. CODE AISC UNIFIED 2010
56. METHOD ASD
57. FYLD 36 ALL
58. FU 58 ALL
59. LX 56 ALL
60. TRACK 2 ALL
61. CHECK CODE ALL
STEEL DESIGN
STAAD SPACE -- PAGE NO. 6
STAAD.PRO CODE CHECKING - ( AISC-360-10-ASD) v1.4a
********************************************
ALL UNITS ARE - KIP INCH (UNLESS OTHERWISE Noted)
MEMBER TABLE RESULT/ CRITICAL COND/ RATIO/ LOADING/
FX MY MZ LOCATION
=======================================================================
1 LD L40356 (AISC SECTIONS)
PASS Eq. H2-1 0.945 4
80.00 C 0.00 0.00 0.00
|-----------------------------------------------------------------------|
| SLENDERNESS |
| Actual Slenderness Ratio : 76.914 L/C : 4 |
| Allowable Slenderness Ratio : 200.000 LOC : 0.00 |
|-----------------------------------------------------------------------|
| STRENGTH CHECKS |
| Critical L/C : 4 Ratio : 0.945(PASS) |
| Loc : 0.00 Condition : Eq. H2-1 |
|-----------------------------------------------------------------------|
| DESIGN FORCES |
| Fx: 8.000E+01(C ) Fy: 0.000E+00 Fz: 0.000E+00 |
| Mx: 0.000E+00 My: 0.000E+00 Mz: 0.000E+00 |
|-----------------------------------------------------------------------|
| SECTION PROPERTIES (UNIT: INCH) |
| Azz: 2.625E+00 Ayy: 1.500E+00 Cw: 0.000E+00 |
| Szz: 0.000E+00 Syy: 0.000E+00 |
| Izz: 8.350E+00 Iyy: 1.541E+01 Ix: 2.512E-01 |
|-----------------------------------------------------------------------|
| MATERIAL PROPERTIES |
| Fyld: 36.000 Fu: 58.000 |
|-----------------------------------------------------------------------|
| Actual Member Length: 96.000 |
| 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 10.67 N/A 12.77 T.B4.1(a)-3 |
| N/A N/A N/A N/A N/A |
| Flexure : Compact 9.33 15.33 25.83 T.B4.1(b)-12 |
| N/A N/A N/A N/A N/A |
STAAD SPACE -- PAGE NO. 7
STAAD.PRO CODE CHECKING - ( AISC-360-10-ASD) v1.4a
********************************************
ALL UNITS ARE - KIP INCH (UNLESS OTHERWISE Noted)
|-----------------------------------------------------------------------|
| CHECK FOR AXIAL TENSION |
| |
| FORCE CAPACITY RATIO CRITERIA L/C LOC |
| Yield 0.00E+00 1.16E+02 0.000 Eq. D2-1 4 0.00 |
| Rupture 0.00E+00 1.55E+02 0.000 Eq. D2-2 4 0.00 |
|-----------------------------------------------------------------------|
| CHECK FOR AXIAL COMPRESSION |
| |
| FORCE CAPACITY RATIO CRITERIA L/C LOC |
| Maj Buck 8.00E+01 8.46E+01 0.945 Eq. E3-1 4 0.00 |
| Min Buck 8.00E+01 9.76E+01 0.820 Eq. E3-1 4 0.00 |
| Flexural |
| Tor Buck 8.00E+01 9.05E+01 0.884 Eq. E4-1 4 0.00 |
| Intermediate |
| Results Eff Area KL/r Fcr Fe Pn |
| Maj Buck 5.36E+00 76.91 2.64E+01 4.84E+01 1.41E+02 |
| Min Buck 5.36E+00 56.61 3.04E+01 8.93E+01 1.63E+02 |
| Flexural Ag Fcr Pn |
| Tor Buck 0.00E+00 2.82E+01 1.51E+02 |
|-----------------------------------------------------------------------|
| CHECK FOR SHEAR |
| |
| FORCE CAPACITY RATIO CRITERIA L/C LOC |
| Local-Z 0.00E+00 3.40E+01 0.000 Eq. G2-1 4 0.00 |
| Local-Y 0.00E+00 1.94E+01 0.000 Eq. G2-1 4 0.00 |
| Intermediate |
| Results Aw Cv Kv h/tw Vn |
| Local-Z 2.62E+00 1.00 1.20 9.33 5.67E+01 |
| Local-Y 1.50E+00 1.00 1.20 10.67 3.24E+01 |
|-----------------------------------------------------------------------|
| CHECK FOR BENDING-YIELDING |
| |
| FORCE CAPACITY RATIO CRITERIA L/C LOC |
| Major 0.00E+00 1.03E+02 0.000 Eq. F9-1 4 0.00 |
| Minor 0.00E+00 1.37E+02 0.000 Eq. F6-1 4 0.00 |
| Intermediate Mn My |
| Major 1.72E+02 0.00E+00 |
| Minor 2.29E+02 0.00E+00 |
|-----------------------------------------------------------------------|
| CHECK FOR BENDING-LATERAL TORSIONAL BUCKLING |
| |
| FORCE CAPACITY RATIO CRITERIA L/C LOC |
| Major 0.00E+00 1.39E+03 0.000 Eq. F9-4 4 0.00 |
| Intermediate Mn Me Cb Lp Lr Lb |
| Major 2.32E+03 0.00E+00 1.00 0.00 0.00 96.00 |
STAAD SPACE -- PAGE NO. 8
STAAD.PRO CODE CHECKING - ( AISC-360-10-ASD) v1.4a
********************************************
ALL UNITS ARE - KIP INCH (UNLESS OTHERWISE Noted)
|-----------------------------------------------------------------------|
| CHECK FOR FLEXURE TENS/COMP INTERACTION |
| RATIO CRITERIA L/C LOC |
| Flexure Comp 0.945 Eq. H2-1 4 0.00 |
| Flexure Tens 0.000 Eq. H2-1 4 0.00 |
| Intermediate frbw / frbz / fra / |
| Fcbw Fcbz Fca |
| Flexure Comp 0.00E+00 0.00E+00 1.49E+01 |
| 3.45E+01 3.45E+01 1.58E+01 |
| Flexure Tens 0.00E+00 0.00E+00 0.00E+00 |
| 1.48E+01 3.45E+01 2.16E+01 |
|-----------------------------------------------------------------------|