Options

The Options menu provides a range of design options to control various parameters within the design of a range of connections. The Options menu also controls the Design Code to be used for the Design.

The basic layout of the Options menu is shown below.

Design Options

The Design Options provide control over the design methods adopted for a range of the connection types. These options apply to both the standalone and integrated design modes. The design options are Global settings, in that they will apply to all connections designed within a connection file. The various options available in the Design Options menu control a wide range of aspects of the connection design.

On selecting the Design Options menu item, the Connections Default Setting pop-up window will open. Depending on the type of connection currently being viewed the Connection Default Settings window will open in the tab appropriate to that connection.

General Tab

The General Tab provides a number of design options which control the design model for moment connections, control the level of detail provided in the design outputs and a range of options which control the design and detailing of bolts and welds in both moment and simple connections. The layout of the General Tab is shown below.

The available options are:

Use SCI Green Book - the default option to use the SCI Green Books. Alternatively an older Blue Book based elastic design can be used

Reduced Output - prints a summary of the design output

Ignore 1.4 diameter edge distance - ignore the standard 1.4 edge distance criteria and uses a 1.25 * diameter edge distance, applicable to machine cut or rolled edges.

Deduct 2*tw from flange fillet welds - if the end-plate does not extend enough to permit a weld return, the design weld length is based on the weld length minus 2 times the throat thickness

HSFG Bolts slip resistance - consider HSFG bolts to be non slip under either serviceability or ultimate limit state

Ultimate/Service force factor - select the factor to estimate the serviceability forces from an ultimate limit state

Welds Default sizes - defined weld sizes for use in the auto-design

Round weld sizes - the default weld sizes are based on geometric rules which can result in welds being specified in decimal places. The rounding options controls how the default weld sizes are then specified.

Weld type - select the type of weld used in the connection design

Eaves Apex Tab

The Eaves and Apex Tab provides options to control the design of eaves and apex moment connections. The options available cover the options for both design and detailing of both eaves and apex type moment connections. The tab also contains a number of options for use with the older Blue Book design mode. The layout of the Eaves Apex Tab is shown below.

The available options are:

Design flange compression welds - while direct bearing is permitted, this options will design the welds to transfer the compressive force

Allow flush end plate - allow the end plate to end flush with the top of the top flange (or underside of the bottom flange)

Always use triangular bolt force - the SCI Green Book methodology allows for a plastic distribution of forces in the bolts, based on the ductility of the end plate. This options always uses a triangular elastic force distribution

Draw nut on End-plate side (eaves only) - this option reverses the orientation of the bolt. This can allow bolts to be placed closer to the flange of the beam or haunch

Rigid Unbraced Multi-Storey Frame - for a rigid unbraced multi-storey frame, the failure mode of each bolt row must be Mode 3 (bolt failure without end plate prying) to control deflections

Portal or Rigid Braced multi-storey frame - failure by any of the modes 1, 2 or 3 is permissible. The joint is still classified as rigid.

Use simple method to achieve all mode 3 - ignore prying force so failure occurs only by mode 1 or 3.

Always use cl 6.3.4.2 - from BS 5950, ignore the prying forces for all bolts rows, not only that fail the Mode 3 check

Allow end plate under-sizing by - option to reduce the width of end plates below the width of the attached member. The drop down contains the limit the width cannot be reduced by more than.This option also affects baseplates. The end plate and baseplate width is input by the user.

Haunch cut deductions - deductions made to the haunch section as part of the cutting process

Non Green Book options

Allow web tension sharing -  Design web tension for adjacent groups of bolts, averaging out the forces as would happen in reality.

Allow Rafter Flange Over Stressing -  As per Green Book allows over-stressing of the rafter flange/web in compression as it is really in bearing: 40% if only the flange is in compression, 20% if flange and web are in compression.

Design Flange Weld for 2 Rows of Bolts - As per Green Book, the flange weld should resist the forces from the first two rows of bolts inside the flange, plus any row outside. This is very onerous, but is designed to prevent the flange weld being the weakest component.

Limit Web Shear Double Plate Capacity -  As per Green Book, the doubler plate only increase the web shear capacity by 75%.

Base Plates

The design and detailing option for the base plate design are given in the Base Plates tab. The layout of this tab is as shown below.

The available options are:

Eurocode - Don't limit compression area to plate capacity - with this option disabled the compression area is limited to ensure the bending of the base plate is not leading to over stressing

Optimise Base compression area - reduce the compression to the minimum area required

Use gross web compression area - do not reduce the area of the compression zone over the flange area, using the width of zone based on the flange width

Use gross flange compression width - utilise the full width of the base plate in the compression zone

Limit Pressure to base-plate capacity - reduce the concrete compression capacity until the base plate capacity is not exceeded. This can reduce the moment and hence the force in the compression and tension zones

Uni-directional tension bending only - in the tension zone, do not use bi-directional bending for the internal bolts. Only applies to non-stiffened base plates

Use Min projection - use the minimum area to resist the compression force in the compression zone

Ignore Horizontal Shear - if shear force is to be resisted by means other than the column base, no shear design is done and the shear force is ignored

Ignore Bolt shear resistance - for bases where shear design is required, the contribution of the bolts to the shear resistance can be ignored

Design Slab Bases as axial using P1 if P2 >= 0.75*P1 (Blue Book method) - for bases with a small moment resulting in pressure over the whole of the base, if P2 >= 75% of P1, the pressure under the base is taken to be equal to P1 and the base designed as an axially loaded base, ignoring the moment.

Base Friction - the coefficient of friction for resistance to horizontal shear

Fcu Compression coeff - coefficient for the compressive strength of the concrete

Tension bolt yield line limits - No limits are paces on the width over yield lines. An older SCI publication gave a recommendation f 3.5 times the lever arm 'm'.

Default Defusion ratio alpha - the ratio of the diffusion of the compressive force through the concrete. The default UK value is 1.5.

Web weld length - the length of weld over the web specified as a percentage.

Use 4d washer size for pullout design - use the Green Book recommendation of 5*d x 5*d x 0.8*d for the washer size, based on the holding down bolt diameter d.

Splices

The design options for both column and beam splices are given under the Splices tab.

The design options for splices contains only a single option.

Check for net tension in Non HSFG bolts - This calculates the tension in non-High Strength Friction Grip (HSFG) bolts in the splice. “Net tension is considered significant when it exceeds 10% of the design strength (Py) of the upper column”, C. 7.2 BCSA Joints in Steel: Simple Connections.

Simple Joints

The design and detailing options for

The available options are:

Beam to Column Web beams: Minimum flange clearance - for beams connected to a column web, the beam flange will be notched to give the minimum stipulated side clearance

Beam to Column web fin-plates: strip 1 side of flange - for beams connecting to a column web, the beam is lowered into position, which can lead to a clash with the fin plate. The flanges can be cut back on 1 side of the beam to avoid this clash. This will reduce the section capacity.

Beam to Beam Notch: notch flange clearance - for beam to beam connections, the depth of the notch can be specified as a clearance relative to the underside of the flange of the supporting beam

Flexible End-plates Flush on top - allow flexible end plates to be drawn level with the top of the top flange (and underside of the bottom flange).

Full Depth Flexible End Plates - draw flexible end plates as full depth depth plates.

Fin Plates use Rigid Support Model - the fin plate is assumed to be a rigid cantilever. Therefore, the rotation of the supported beam will induce additional moments and shear on the bolts and welds.

For simple connection design, it is necessary to consider the tying force as part of the robustness design criteria. In both the BS and EC design, the minimum design tie force is the greater of 75kN or the shear force on the beam. However, in line with SCI P341, the value of the shear force can be reduced (to a minimum of 75kN) depending upon the number of storeys within the building, when designing to the British Standard. This aspect of the design in controlled by the BS - Min Tie Force drop down.

Similarly, for the design of tying force to the EuroCode, rather than use the shear force on the beam for the tying force, it is possible to over-ride the tie force using the EC- Do not use factored shear force in considering maximum tie force option. In this case, the user must manually evaluate the tie force and input this in the Tie Force input area.