Beam End Connection

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Practice 995 215 1210

Date 30Aug99

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FLUOR DANIELFLUOR DANIEL

BEAM END CONNECTIONS

9952151210.doc Structural Engineering

PURPOSE

This practice establishes guidelines for the design of flexible end plate and web side plate beam end connections.

SCOPE

This practice covers the methods used in the design of flexible end plate and web side plate beam end connections. Diagrams showing the connection arrangements are givenin Attachment 1. Design capacity charts for Fluor Daniel standard detail drawings aregiven in Attachment 2. The design procedure is given, which can be used for the design

of non-standard connections. The procedure is based on limit states design to AS 4100and the AISC publication Standardised Structural Connections.

APPLICATION

This practice can be used for design of beam pin connections in steel structures, i.e.

where there is no requirement for moment to be transferred.

NOTE: This practice has not been updated to include the lightweight BHP sections or

the effect on section capacities caused by the introduction of Grade 300 steel sections.Hence use of the design capacity charts in Attachment 2 may lead to conservativedesign.

Flexible end-plate

connection

Flexible end plate connections are generally preferred as they are slightly moreeconomical than other beam end connection types and there is little eccentric moment

generated at the joint. These connections generally have a higher capacity than acomparable web side plate connection. However, they can cause difficulties inconstruction when installing a beam between two existing beams or columns.

Web side-plate

connection

Web side plate connections are preferred if axial beam forces are to be transferred.Beams with web side plate connections are easier to erect than beams with flexible end

plate connections.

NOTATION

The dimensional units for length, force and stress in all expressions or equations are to be

taken as millimetres (mm), newtons (N) and megapascals (MPa) respectively.

As Net area of web in shear At Net area of web in tension

dw Depth of web at cope(s)

e Eccentricity of section from assumed pin location (face of end plate for flexible

end plate connections, centroid of bolts for web side plate connections)e p Eccentricity of plate section from assumed pin location

f u Tensile strengthf uw Nominal tensile stress in weld

f va* Average design shear stress in the webf vm* Maximum design shear stress in the webf y Yield stress



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l p Length of end plate or web side plateLw Total length of weld

M p Plate moment capacityMs Section moment capacity

n Number of bolt rows N Total number of bolts

t p Thickness of end platett Design throat thickness of fillet weld

tw Thickness of beam web

V b Bolt group shear capacityVdes Design shear strength of connection

Vf Shear capacity of a bolt (taking account of reduction factor for bolted joints >300mm long)

V p Plate shear capacityV pm Plate shear capacity at support with moment interaction

Vu Beam web shear capacity at copeVum Beam web shear capacity at cope with moment interactionVv Beam web shear capacity at connection to plateVw Weld shear capacity

Vwb Web block shear capacity

Z b Effective number of bolts loaded in vertical shear in the bolt group. Refer AISCStandardised Structural Connections, Part B, Section 5.12.

Strength reduction factor

DESIGN LOADS

Loads will be determined in accordance with AS 1170 SAA Loading Code.

STANDARD DETAILS

The capacity tables (Attachment 2) and standard drawings adopt three options for the

number of bolts in the connection.

n Type 1 - the suggested minimum number of bolts per connectionn Type 2 - an intermediate number of bolts per connection

n Type 3 - the maximum number of bolts per connection

STANDARD DRAWINGS

Refer to the following FD standard drawings for standard details:

n

FDS2A1 Flexible end plate connections - rolled sectionsn FDS2A2 Web side plate connections - rolled sections - 1 bolt columnn FDS2A5 Web side plate connections - rolled sections - 2 bolt columnsn FDS2A6 Flexible end plate connections - welded sections

n FDS2A7 Web side plate connections - welded sections - 1 bolt columnn FDS2A8 Web side plate connections - welded sections - 2 bolt columns



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CONNECTION DETAILSThe following materials have been adopted for the standard connections:

n 250 grade steel plate to AS 3678n M20 8.8N/S boltsn 6 mm fillet welds of category SP with E48XX electrodes for flexible end plate

connectionsn 8 mm fillet welds of category SP with E48XX electrodes for web side plate

connections

Connections must have a minimum shear capacity of 40 kN, in accordance with Clause

9.4.1(b)(ii) of AS 4100.

The designer must check the web bearing capacity of 410 UB 60 and 200 UC 52 andlighter supporting beams where they are used to support beams connected on both sides

of the web by flexible end plate connections.

CONNECTION DESIGN

The connection design shear capacity is taken as the minimum of the shear capacities as

defined below. The connections are treated as pinned, and therefore it is assumed that nomoment is transferred through the connection. The connections provide partial torsionalend restraint.

FLEXIBLE END PLATE

SHEAR CAPACITY

V des = min [ V p, V b, Vw, Vu, Vv, Vum]

Plate capacity

Shear capacity of end plate:

V p = 0.6 f y l p t p 4 / [0.9 + (f vm*/f va

*)]

= f y l p t p

where = 0.90

Bolt capacity

Shear capacity of bolt group:

V b = 2 n V f

where = 0.80

Weld capacity

Capacity of the weld group:

V w = 0.6 f uw t t L w

where = 0.80



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Beam web shearcapacity

The shear capacity of the beam web is calculated assuming a uniform shear distributionin the web at the critical section for uncoped beams, varying to a parabolic distribution indouble-coped beams.

No cope: Vu = 0.6 f y t w d w

Single cope: Vu = 0.6 f y t w d w 2 / [0.9 + (f vm*/f va*)]

≈ 0.54 f y t w d w

Double cope: Vu = 0.6 f y t w d w 2 / [0.9 + (f vm*/f va*)]

= 0.5 f y t w d w

where = 0.90

Beam web shear

capacity at plate

The shear capacity of the web at the connection to the plate is calculated assuming auniform shear distribution in the web.

V v = 0.6 f y t w l p

where = 0.90

Beam web shear

capacity for

moment at cope

The shear capacity at the coped section is calculated allowing for moment-shear

interaction. The connection is assumed to act as a pin at the face of the end plate, henceat the end of the cope a moment is developed which reduces the shear capacity of thesection at this location.

If e ≤ 0.75 M s / V u then:

V um = V u

If 0.75 Ms / V u ≤ e ≤ 1.667 M s / V u then:

V um = 2.2 V u / [1 + (1.6 e V u / M s)]

If e ≥ 1.667 M s / V u then:

V um = M s / e

Refer AS 4100 Supp.1 C5.12.3 and AS 4100 5.12.3 for shear & bending interaction.



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WEB SIDE PLATESHEAR CAPACITY

V des = min [ V p, Vup, V b, Vw, Vu, Vum, Vwb]

Plate capacity

Shear capacity of the web side plate:

V p = 0.6 f y l p t p 2 / [0.9 + (f vm*/f va

*)]= 0.5 f y l p t p

where = 0.90

Plate capacity

adjusted for moment

The shear capacity at the point where the plate is welded to the supporting structure is

calculated allowing for moment-shear interaction. For web side plate design, theconnection is assumed to act as a pin at the centroid of the bolts, hence a moment isdeveloped at the end of the plate which reduces the shear capacity of the plate at thislocation.

If e p ≤ 0.75 M p / V p then:

V pm = V p

If 0.75 M p / V p ≤ e p ≤ 1.667 M p / V p then:

V pm = 2.2 V p / [1 + (1.6 e p V p / M p)]

If e p ≥ 1.667 M p / V p then:

V pm = M p / e p


Bolt capacity

Shear capacity of the bolt group:

V b = Z b V f

where = 0.80

Weld capacity

Capacity of the weld group:

V w = 0.6 f uw t t L w

where = 0.80

Beam web shear

capacity

The shear capacity of the beam web is calculated assuming a uniform shear distribution

in the web for uncoped beams, varying to a parabolic distribution in double-coped beams.

No cope Vu = 0.6 f y t w d w



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Single cope Vu = 0.6 f y t w d w 2 / [0.9 + (f vm*/f va*)]≈ 0.54 f y t w d w

Double cope Vu = 0.6 f y t w d w 2 / [0.9 + (f vm*/f va*)]

= 0.5 f y t w d w

where = 0.90

Beam web shear

capacity for

moment at cope

The shear capacity at the coped section is calculated allowing for moment-shear interaction. The connection is assumed to act as a pin at the point where the web plate iswelded to the supporting member, hence a moment is developed in the coped section

which reduces the shear capacity of the section at this location.

If e ≤ 0.75 M s / V u then:

V um = V u

If 0.75 Ms / V u ≤ e ≤ 1.667 M s / V u then:

V um = 2.2 V u / [1 + (1.6 e V u / M s)]

If e ≥ 1.667 M s / V u then:

V um = M s / e

where = 0.90


Web block shear

capacity

For coped beams a block shear failure around the bolt region due to shear and tension can

occur.

V wb = (0.6 A s f y + 0.85 A t f u)

where = 0.90



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REFERENCESAS 1170 SAA Loading code.

AS 1554 Structural steel welding.

AS 3678 Structural steel - Hot-rolled plates, floor plates and slabs.

AS 4100 Steel structures.

AS 4100 Supplement 1 - Steel structures - Commentary.

Hogan,T.J. & Firkins,A., Standardised Structural Connections, Part A: Details and Design Capacities. Australian Institute of Steel Construction Ltd, 1978.

Hogan,T.J. & Thomas,I.R., Standardised Structural Connections, Part B: Design

Models. Australian Institute of Steel Construction Ltd, 1978.

Hogan,T.J. & Thomas,I.R., Design of structural connections. 4th edition. AustralianInstitute of Steel Construction Ltd, 1978.

Pham,L. & Mansell,D.S., Comparison of Working Stress Design and Limit States Designof Steel Shear Connections. The Institution of Engineers Australia, StructuralEngineering Conference, Adelaide, October 1990.

ATTACHMENTS

Attachment 1 (30Aug99) ................................................................Beam end connections

Attachment 2 (30Aug99)...................................................Tables of connection capacities



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Attachment 01 - Sheet 1 of 2



Beam End Connections

9952151210a01.doc Structural Engineering



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Beam End Connections




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Tables of Connection Capacities




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Beam End Connection