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Practical Steel Connection Software Design Using AISC 2010 Standard
Including:Practical Advice for Reviewing Software
Generated Connection Designs
Steve Ashton, P.E., SECB
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Limit States that Changed
Bolt Limit States
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Bolt Materials
Group A: (Includes A325 and F1852)Fu = 120 ksi *
Group B: (Includes A490 and F2280)Fu = 150 ksi
(* ‐ up to 1” diameter)
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Allowable Shear Strength
1989 2005 2010A325N 21 ksi 24 ksi 27 ksiA325X 30 ksi 30 ksi 34 ksiA490N 28 ksi 30 ksi 34 ksiA490X 40 ksi 37.5 ksi 42 ksi
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Table J3.2 ‐ 2005
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Table J3.2 ‐ 2010
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Bolt Limit States
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Slip Critical Joints ‐ 2005 SpecificationRn = μDuhscTbNs (J3‐4)
Prevention of Slip is a Serviceability Limit StateLRFD: = 1.00ASD: = 1.50
Prevention of Slip at Required Strength LevelLRFD: = 0.85ASD: = 1.76
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Rn = μDuhscTbNs (2005 ‐ J3‐4)
= 0.35 (Class A) = 0.50 (Class B)
Rn = μDuhfTbNs (2010 ‐ J3‐4)
= 0.30 (Class A) = 0.50 (Class B)
Slip Critical Joints
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Rn = μDuhscTbNs (2005 ‐ J3‐4)
hsc = 1.00 (STD)hsc = 0.85 (OVS or SSL)hsc = 0.70 (LSL)
Rn = μDuhfTbNs (2010 ‐ J3‐4)
= 1.00 (STD) = 0.85 (OVS or SSL) = 0.70 (LSL)
Slip Critical Joints
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Slip Critical Joints ‐ 2010 Specification
Rn = μDuhfTbNs (J3‐4)
hf = 1.00 (0 or 1 Filler)hf = 0.85 (2 or more Fillers)
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Limit States
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New Section J4.5
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Other 14th Ed. Changes• Prying Action• Single Plate Shear Connections (Shear Tabs)• Fillers• New Tables
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Other 14th Ed. Changes
• Prying Action• Single Plate Shear Connections (Shear Tabs)• Fillers• New Tables
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Prying Action (ASD)
With prying action:
T = required strength per boltp = tributary length per bolt line ≤ 2b = 1‐ d’ / pd’ = width of hole along length of fitting
)'1('4
min
upF
Tbt
Prying Action Nomenclature
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Prying ActionDouble Angle Connection
Expanded Bolt Spacing
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Wide Gage
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Narrow Gage
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Narrow Gage and Expanded Bolt Spacing
Other 14th Ed. Changes
• Prying Action• Single Plate Connections (Shear Tabs)• Fillers• New Tables
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Conventional Configuration
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Conventional Configuration
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Single‐Plate Connection
Conventional Configuration
13th Edition Manualtp or tw ≤ d/2 + 1/16”
14th Edition ManualNo requirement if n ≤ 5 and SSLT
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Single‐Plate Connection
Conventional Configuration
13th Edition ManualEccentricity can be ignored if:
n ≤ 9 and STD or n ≤ 12 and SSLT
14th Edition ManualEccentricity always considered per Table 10‐9
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Other 14th Ed. Changes• Prying Action• Single Plate Shear Connections (Shear Tabs)• Fillers• New Tables
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Fillers
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Fillers: J5 ‐ 2005
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Fillers: J5.2 ‐ 2010
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Fillers: J5 – 2010 Commentary
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Other 14th Ed. Changes• Prying Action• Single Plate Shear Connections (Shear Tabs)• Fillers• New Tables
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14th Edition Manual
New Tools• Table 8‐12. Approx. Number of Passes for Welds• Table 10‐13. Min. Inside Radius for Cold‐Bending• Table 10‐14. Clearances for Skewed Connections• Table 10‐15. Seated Connections to HSS
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14th Edition Manual
New Tools• Table 8‐12. Approx. Number of Passes for Welds• Table 10‐13. Min. Inside Radius for Cold‐Bending• Table 10‐14. Clearances for Skewed Connections• Table 10‐15. Seated Connections to HSS
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Tables 10‐13 and 10‐14
14th Edition Manual
New Tools• Table 8‐12. Approx. Number of Passes for Welds• Table 10‐13. Min. Inside Radius for Cold‐Bending• Table 10‐14. Clearances for Skewed Connections• Table 10‐15. Seated Connections to HSS
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Table 10‐15
Practical Steel Connection Software Design Using AISC 2010 Standard
Practical Advice for Reviewing Software Generated Connection
Designs
Software Generated Calculations
Reviewing Software Generated Connection Designs
• Look at Every Connection• Know the Required Strengths• Determine the Load Path• Estimate the Capacity
– See “Evaluating a Connection” Handout– Quick Hand Calculations (Numbers to Memorize)– Printed Calculations
• Evaluate Constructability!
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Reviewing Software Generated Connection Designs
• Look at Every Connection• Know the Required Strengths• Determine the Load Path• Estimate the Capacity
– See “Evaluating a Connection” Handout– Quick Hand Calculations (Numbers to Memorize)– Printed Calculations
• Evaluate Constructability!
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Reviewing Software Generated Connection Designs
• Look at Every Connection• Know the Required Strengths• Determine the Load Path• Estimate the Capacity
– See “Evaluating a Connection” Handout– Quick Hand Calculations (Numbers to Memorize)– Printed Calculations
• Evaluate Constructability!
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Required StrengthsAISC COSP Section 3.1.2
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Transfer Forces
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Transfer Forces
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Transfer Forces
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Transfer Forces
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Transfer Forces
Reviewing Software Generated Connection Designs
• Look at Every Connection• Know the Required Strengths• Determine the Load Path• Estimate the Capacity
– See “Evaluating a Connection” Handout– Quick Hand Calculations (Numbers to Memorize)– Printed Calculations
• Evaluate Constructability!
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Load Path ‐ Uniform Force Method
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AISC Nomenclature
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Column Forces
Beam forces
Where
and
PreP
rV c
c cH
PreP
rH b
b bV
22bc eer
Uniform Force Method(Equations from Manual)
cb ee tantan
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Uniform Force Method (Traditional)
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Connection Calculations
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Uniform Force Method (Compact Gusset)
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Connection Calculations
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Workpoint Relocation (Special Case 1)
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Workpoint Relocation (Special Case 1)
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Workpoint Relocation (Special Case 1)
Reviewing Software Generated Connection Designs
• Look at Every Connection• Know the Required Strengths• Determine the Load Path• Estimate the Capacity
– See “Evaluating a Connection” Handout– Quick Hand Calculations (Numbers to Memorize)– Printed Calculations
• Evaluate Constructability!
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Calculating Capacity
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Calculating Capacity
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Calculating Capacity10 Numbers to Memorize (2010 ASD)
• 0.928• 27• 45• 1.25• 1.3• 3.4• 0.5• 0.6• 1.2• 1.5
Reviewing Software Generated Connection Designs
• Look at Every Connection• Know the Required Strengths• Determine the Load Path• Estimate the Capacity
– See “Evaluating a Connection” Handout– Quick Hand Calculations (Numbers to Memorize)– Printed Calculations
• Evaluate Constructability!
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Constructability
Constructability
Constructability
Constructability
Constructability
Constructability
Constructability
Connection Costs
Connection Costs
Connection Costs
Connection Costs
SummaryReviewing Software Generated Connection
Designs• Look at Every Connection• Know the Required Strengths• Determine the Load Path• Estimate the Capacity
– See “Evaluating a Connection” Handout– Quick Hand Calculations (Numbers to Memorize)– Printed Calculations
• Evaluate Constructability!
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