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The Beam Splice connection is intended for use in the design of splice connections to open I of H-sections subjected to major and minor bending, transverse vertical and horizontal shear and axial forces. A beam splice can be designed with either bolted web cover plates or bolted web end plates. For design to the Eurocode, the moment and axial force are resisted by a combination of both the flange and web plates, with the forces being distributed in proportion to the relative stiffnesses of the flanges and web.
A typical layout of the Beam splice connection is shown below.
The General area provides inputs to name the connection brief and also to apply a title to the current loadcase, for non-linked connection design. In the case of a linked connection design, the loadcases and load cases titles will be taken from the Masterframe model. The default layout of the General area is shown below.
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The forces input area provides inputs for the major and minor bending moments, horizontal and vertical shear forces and the input for the axial force in the connection. In a linked connection, these forces are taken from the analytic model. The Forces area also provides an input to specify the minimum flange forces, input as a percentage of the flange capacity. For a standalone connection, the default forces are zero. The general layout of the Forces area is shown below. Since the design is based on the ultimate limit state, the input forces should be factored.
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Moment xx - major axis moment
Shear xx - vertical shear force
Axial force - the axial force at the splice location. A positive input is taken as a compressive force
Shear yy - horizontal shear
Print Case - sets the current load case to print or excludes it from printing
Minimum Flange Force - the minimum force in the flange, specified as a percentage of the flange capacity
The Beam Properties area provides inputs to define the beam section which is to be spliced. It is also possible to input the gap between the beam sections, with a gap of zero giving direct bearing in the compression zone.
The layout of the beam properties area is shown below.
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The default section in a standalone connection is a 457x191UB67. In a linked connection, the beam section is defined by the Masterframe model. To define the beam section, the Beam area is expanded by clicking on the arrow to the left of the Beam row. The expanded area is shown below.
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Steel Grade - the grade of the section
Section Type - section type selection. Only open I- or H-sections can be used
Section - the currently selected section
Cell depth - for cell beams, the overall section depth at the splice point
To select the steel grade, section type and section size, each of these inputs can be clicked on the choose the appropriate option can be choose for the dropdown.
The Bolt Details and Weld/Plate Grade are provides inputs to specify the bolts to be used in the splice connection along with inputs to select the steel grade of the flange and web plates. The weld grade will be determined by the plate grade
The bolt type, grades and diameters can be set by expanding the Bolt row. This is achieved by clicking on the arrow to the left of the Bolt Details row. The expanded Bolt Details row is shown below.
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Each row can be selected by clicking with the mouse and expanding the drop down icon to access the required options. The calculations will automatically update to reflect the selected option.
Similarly, the grade for the plates to be used is selected by clicking on the Plate Grade row and selecting the required steel grade from the drop down.
Splice connections must be rigid in classification. To achieve this, the connections need to be designed to be slip resistant. A splice connection can be designed as slip resistant at serviceability limit state, or, alternatively, to be slip resistant at ultimate limit state. These options can be set using the Options>Design Options menu. Refer to the Options section of this manual for more details.
To achieve slip resistance, generally, pre-loaded bolts will be required. However, in the UK, ordinary bolts in close tolerance holes are also considered to be satisfactory to resist slippage. To achieve this classification, the hole diameter must be set to be 1mm greater than the bolt diameter. This can be achieved by expanding the Hole Dia. row and selecting the appropriate hole diameter.
The Flange plates area provides input to define the properties of the flange plates as used in the beam splice connection. The inputs allow both inner and/or outer flange plates to be defined. The default layout of the Flange Plates area is shown below.
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The Top and Bottom flange plate areas are expanded by clicking on the arrow to the left of the relevant row. The inputs in each area are the same. The default setup of a splice connection is to have top and bottom outer plates but no inner plates. The presence of the inner and outer plates is controlled by the plate thickness input. An input of zero means that plate is not included.
The expanded Top Flange area is shown below. By default the top and bottom flange plates are set to 12mm thick plates and exterior plates only.
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Number of bolt rows - input the number of rows of bolts. The default value is two.
Bolt Long c/c - the longitudinal centres of the bolts.
Bolt Outer Horiz c/c - the transverse bolt centre-to-centre spacing for the outer set of bolts
Bolt Inner Horiz c/c - the transverse bolt centre-to-centre spacing for the inner set of bolts
End Distance - the distance from the end of the last bolt row to the end of the flange plate.
Bolt Centre gap - the horizontal centre-to-centre bolt spacing for the bolts either side of the splice location
Countersunk - select whether or not the bolts are to be countersunk. The default is non-countersunk bolts
Stagger Pattern - define whether or not the bolts are to be staggered and the stagger pattern
Weld Size - input the weld size (mm). A value of zero means no welds.
The Weld size input is used to define a flange plate which welded to one beam and bolted to the other. This option is only available when only outer flange plates are used.
The inputs for the inner flange plates control the plate thickness and plate width only, since the bolt arrangements are set in the outer flange plate inputs. A beam splice is required to have a minimum minor axis capacity, which cannot be achieved by the inner flange plates since the inner flange plates cannot be a single plate due to the presence of the beam web, hence a beam splice always requires outer flange plates.
The Web Cover plate area provides inputs to define the plate geometry and size used in the beam splice, along with inputs to define the bolt properties and arrangement. This area also allows for the choice of web cover plates of web end plates to be made. The default layout out of the Web Cover Plates area is shown below.
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Cover or End plates - select the type of end plates
Plate thickness - select the thickness for the web cover plate
Number of plate - web cover plates can be single or double sided Input 1 for a single side web cover plate. Inputting any number greater than 1 is interpreted to mean double sided plates
Width - input the width of the web plate
Bolt Cross c/c - input the number of bolt rows and the bolt row centres along the width of the plate. To input the parameters, expand the line by selecting the arrow to the left of the row
Bolt Long c/c - input the number of bolts across the length of the web plate. To input the parameters, expand the line by selecting the arrow to the left of the row
End Distance - input the distance of the edge of the web cover plate from the last row of bolts
Bolt centre gap - the gap in the centre column of bolts either side of the splice location
Staggered Pattern - bolts in the web plate can be set as staggered by expanding the line and selecting the stagger option from the drop down
The bolts in the web plate are symmetrically arranged about the splice location. The bolt rows and columns are defined in the inputs in terms of the number of centres, that is, the number of gaps, rather than the number of rows of columns.
With the Web End Plate option selected, the input area is amended to reflect the connection geometry. The Web End Plates area is as shown below.
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Cover or End plates - notes the use of web end plates. The selection can be changed by clicking in the right hand box and using the drop down
Thickness - the thickness of the end plate. The default thickness is 10mm. The input is changed by selecting the entry and over-typing
Bolt Cross c/c - the centres of the inner and outer bolts. To input the parameters, expand the line by selecting the arrow to the left of the row
Number of bolt rows - displays the number of bolts rows. The default is 3 rows. The input is changed by selecting the entry and over-typing
Weld size - input for the web plate to beam weld
Staggered pattern - bolts in the web plate can be set as staggered by expanding the line and selecting the stagger option from the drop down
Ignore friction - ignore the shear between the end plates so that the shear is resisted by the bolts only
Ideally any splices in a member in compression would be located at or near a point of lateral restraint or a point of inflexion. Where this is not possible, account needs to be taken of the second order effects which will be additional to the forces and moments in the member at the splice location. The second order effects as additional moments due to strut actions, moments due to lateral torsional buckling and amplification of the moments due to the eccentricity of the axial force in the member due to the deformed shape under the applied moments.
The SCI Advisory Desk have produced the advice note AD 243 which provides a methodology for determining the additional second order effects. Background to the method covering the need for such additional moments is given in SCI AD 314, with an explanation of the second order effects given in SCI AD 244.
The default Internal Moments area is shown below. The default values are all zero.
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Moment(xx), max (kNm) - the maximum major axis moment between lateral restraints
Lex, Ley - the effective lengths in the major and minor axes.
Lzx, Lzy - the distance from the splice location to the nearest point of inflexion in the major and minor axes
mx, my - the moment modification factor for flexural buckling about the major and minor axes
mLTB and Pb - the equivalent uniform moment factor for lateral torsional buckling and the bending resistance strength for lateral torsional buckling
In both the standalone design and a design for a linked Masterframe model, the user is required to determine the inputs for the Internal Moments. To input the parameters, expand the line by selecting the arrow to the left of the row.
The Splice Rotation area provides input to allow a calculation of the additional deflection for splices designed as standalone connections based on the length of the member and the splice location, as a result of the rotation of the joint due to slippage in the splice. The required inputs are the member overall length and the position of the splice. The additional deflection is calculated assuming the member is simply supported.