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ANSI/AISC 358-10
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ANSI/AISC 358-10
Chapters 1-4
1. General
2. Design Requirements
3. Welding Requirements
4. Bolting Requirements
All connections in this Standard shall be considered to
be fully restrained (Type FR) for purpose of seismic
analysis.Rolled wide-flange or built-up members permitted as
long as conform to cross section profile limitations
applicable to specific connection.
(Additional requirements in Chp. 2 on welding for built-up beams and properties of built-up columns.)
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ANSI/AISC 358-10
Chapters 1-4
1. General
2. Design Requirements
2.4.1 For connection design:
fd= 1.00 for ductilelimit states
fn= 0.90 for nonductile limit states
For available strengths calculated in accordance with
this Standard.
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ANSI/AISC 358-10
Chapters 1-4
1. General
2. Design Requirements
2.4.3 Probable Maximum Moment at Plastic Hinge
Effective plastic sectionmodulus of section (or
connection) at location of
plastic hinge
Factor to account forpeak connection
strength
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ANSI/AISC 358-10
Chapters 1-4
1. General
2. Design Requirements
2.4.3 Probable Maximum Moment at Plastic Hinge
Attempts to account forstrain hardening, local
restraint, additional
reinforcement, other
connection conditions
Unless otherwise specifically
indicated in this Standard
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ANSI/AISC 358-10
Chapters 1-4
1. General
2. Design Requirements
3. Welding Requirements
Points to AISC Seismic Provisions for filler metals and
welding procedures.Specifics for weld tabs and backing bars at beam-to-
column and continuity plate-to-column joints. Also,
requirements for continuity plate welds.
(Also provides information for prohibitedwelds (e.g.,
tack welds to connect backing bar to beam flange),
including how to repair if welded in error).
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ANSI/AISC 358-10
Chapters 1-4
1. General
2. Design Requirements
3. Welding Requirements
4. Bolting Requirements
Points to other standards for fastener and installation
requirements.
Refers to AISC Seismic Provisions for quality control
and quality assurance.
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RBS Concept:
Trim Beam Flanges Near
Connection
Reduce Moment at
Connection
Force Plastic Hinge Away
from Connection
Reduced Beam Section (RBS) Moment Connection
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Example of laboratory performance of an RBS connection:
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Whitewashed connection prior to testing:
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Whitewashed connection prior to testing:
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Connection at 0.02 radian......
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Connection at 0.02 radian......
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Connection at 0.03 radian......
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Connection at 0.04 radian......
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-5000
-4000
-3000
-2000
-1000
0
1000
2000
3000
4000
5000
-0.05 -0.04 -0.03 -0.02 -0.01 0 0.01 0.02 0.03 0.04 0.05
Drift Angle (radian)
BendingM
oment(kN-m)
RBS Connection
Mp
Mp
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ANSI/AISC 358:
Section 5.3 Prequalification Limits for RBS
Beam depth: up to W36 (for rolled shapes)
Beam weight: up to 300 lb/ft
Beam flange: up to 1-3/4 inch thick
Span:depth clear span-to-depth ratio of beam
limited to:
7 or greater for SMF
5 or greater for IMF Lateral bracing requirements and protected zone dimensions
specified
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ANSI/AISC 358:
Section 5.3 Prequalification Limits for RBS
Column depth: up to W36 for wide-flange
up to 24-inches for box columns
Beam connected to column flange
(connections to column web not prequalified)
Refer to Chapter 2 and AISC Seismic Provisions for other
requirements
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ANSI/AISC 358:
Prequalification Requirements for RBS
Beam flange welds: - CJP groove welds- Treat welds as Demand Critical, followAISC
Seismic Provisions
-Weld access hole geometry conforms toAISC
Specification
Beam web to column connection:
- For SMF, use fully welded web connection (CJP
weld between beam web and column flange)
- For IMF, boltedconnection to beam webpermitted if slip-critical and follows restrictions in
Section 5.6
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RBS with weldedweb connection:
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ANSI/AISC 358:
Prequalification Requirements for RBS
Protected Zone
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ANSI/AISC 358:
Prequalification
Requirements for
RBS
Note Section 5.7 for
Fabrication ofFlange Cuts!
(e.g., thermal
cutting tolerances,repair of gouges
and notches)
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Lateral brace at center of RBS - violates Protected Zone
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Examples of RBS Connections.....
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ANSI/AISC 358:
RBS
STEP-BY-STEP
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Bolted Unstiffened and Stiffened Extended End-Plate
Moment Connections
End Plate Connections
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End-Plate Connections
AISC Design Guide
no. 4, 2nd
edition,2003, Murray andSumner
1stedition in 1990
Literature datesback to at least1960s
A number of testsconducted as part ofSAC Joint Venture
End Plate Connections
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End-Plate Connections
Number of possible limit states:
Flexural yielding of beamsection
Flexural yielding of end plates
Tension of end-plate bolts
Shear failure of end-plate bolts
Etc.
Ensure inelastic deformation ofconnection is achieved by beamyielding
Shear resistance from bolts incompression
End Plate Connections
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Sumner, et al., 2000
End-Plate Connections
End Plate Connections
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Sumner, et al., 2000
End-Plate Connections
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End plate and column flange bending strengths are
determined using yield line analysis.
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Unstiffened Flange Stiffened
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Prying Action?
End-Plate connections are required to be
designed as thick plates
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End-Plate
Connections(ANSI/AISC 358-10)
End Plate Connections (ANSI/AISC 358 10)
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End-Plate Connections (ANSI/AISC 358-10)
End Plate Connections (ANSI/AISC 358 10)
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End-Plate Connections (ANSI/AISC 358-10)
No limit on weight per foot of beams or columns
Clear span:depth 7 or greater for SMF, 5 or greaterfor IMF
Column depth limited to beam depth or shallower(also W36 maximum)
Protected zone depends on stiffened/unstiffened,beam flange width and depth
End Plate Connections and Floor Slab
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End-Plate Connections and Floor Slab
SMF systems with concrete structural slabs
prequalified only if: Nominal beam depth not less than 24 in. (in
addition to Section 6.3 requirements)
No shear connectors within 1.5 x beam depth from
face of connected column flange Concrete slab kept at least 1 in. from both sides of
both column flanges (e.g., compressible material ingap between column flanges and concrete slab)
(IMF composite slab detailing also adopts these lasttwo requirements; Section 6.9.6)
Connection Detailing (Section 6 9)
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Connection Detailing (Section 6.9)
Welding details, etc., in Section 6.9 (need and requirements for) Continuity plates as
outlined in Section 6.10 (Design Procedure) andAISCSeismic Provisions
Panel zones and column-beam moment ratios(Section 6.6) refer toAISC Seismic
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End-plate Yield Line Mechanism parameter
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Bolted Flange Plate (BFP)
BFP only prequalified for SMF with concrete
structural slabs if slab kept at least 1 from both
sides of both column flanges.
Seismic Behavior BFP
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Seismic Behavior BFP
Initial yielding of beam at last bolt away
from column face Slip of flange plate bolts (similar level toyielding in beam flange)
Secondary yielding in panel zoneAs expected moment capacity and strain
hardening occur
Limited yielding of flange plateAt maximum deformation
BFP tests
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BFP tests
Sato, A., Newell, J.D., Uang, C.-M. Cyclic Behavior and Seismic Design of
Bolted Flange Plate Steel Moment Connections, AISC Engineering Journal,
Fourth Quarter, 2008.
BFP-3
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BFP-3
Sato, et al., 2008
ANSI/AISC 358
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ANSI/AISC 358:
Section 7.3 Prequalification Limits for BFP
Beam depth: up to W36 (for rolled shapes)
Beam weight: up to 150 lb/ft
Beam flange: up to 1-inch thick
Span:depth clear span-to-depth ratio of beam
limited to:
9 or greater for SMF
7 or greater for IMF
Lateral bracing requirements and protected zone dimensionsspecified
Concrete slab can be utilized (as specified) for lateral bracing
ANSI/AISC 358
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ANSI/AISC 358:
Section 7.3 Prequalification Limits for BFP, contd
Beams shall be connected to flange of the column
Column depth: W36 maximum (for rolled shapes)
W14 maximum if no concrete structural slab
No limit on weight per foot of columns
Width-thickness ratios (beams and columns), lateral bracing,
panel zones, and column-beam moment ratios shall conform to
requirements ofAISC Seismic Provisions.
Section 7 5 Connection Detailing
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Section 7 .5 Connection Detailing
All connection plates
A36 or A572 Gr. 50
Max. overall thickness ;
may use finger shims or shims
with drilled/punched holes
Limit two bolts per row;
symmetrically placed.
Length of bolt group < beamdepth. Standard holes;
oversized in flange plate
only. No punched holes.CJP groove
welds,
demand-critical, any
backing
removed
A490 bolts, threads
excluded from shear plane,
1-1/8 diameter maximum
Section 7 6 Design Procedure
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Section 7.6 Design Procedure
More limit states to consider than some
other connections- e.g., bolt shear, net section fracture,ensuring that beam flange net sectionfracture resistance > yield resistance
W ld d U i f d Fl W ld d W b (WUF W)
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Welded Unreinforced FlangeWelded Web (WUF-W)
ANSI/AISC 358:
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ANSI/AISC 358:
Section 8.3 Prequalification Limits for WUF-W
Beam depth: up to W36 (for rolled shapes)
Beam weight: up to 150 lb/ft
Beam flange: up to 1-inch thick
Span:depth clear span-to-depth ratio of beam
limited to:
7 or greater for SMF
5 or greater for IMF
Lateral bracing requirements and protected zone dimensionsspecified
Concrete slab can be utilized (as specified) for lateral bracing
ANSI/AISC 358:
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ANSI/AISC 358:
Section 8.3 Prequalification Limits for WUF-W, contd
Beams shall be connected to flange of the column
Column depth: W36 maximum (for rolled shapes)
No limit on weight per foot of columns
Width-thickness ratios (beams and columns), lateral bracing,
panel zones, shall conform to requirements ofAISC Seismic
Provisions.
Column-beam moment ratio as specified for SMF; followingAISC
Seismic Provisionsfor SMF
Section 8 5 Beam Flange-to-Column Flange
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Section 8.5 Beam Flange-to-Column Flange
Welds
Weld access hole geometry
and quality shall conform to
AWS D1.8
CJP welds; demand critical,
conform toAISC SeismicProvisions
Section 8 6
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Section 8.6Beam Web-to-
ColumnConnection
Limitations
Shear tab thickness
equal at least to that
of beam web;
overlap with weldaccess holes as
specified
Section 8.7 Design Procedure WUF-W
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Section 8.7 Design Procedure WUF W
Sh=0 value chosen to simplify the design
calculations.Cprvalue calibrated in combination with Sh=0 to
reflect values (moments at column face) measured
in experiments