BS5950 - Connections Handbook

FastrakCSCStructural steelworkanalysis and design

CONNECTIONS

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Connections Documentation page 2 CSCs Offices Worldwide


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Disclaimer page 3Disclaimer CSC (UK) Ltd does not accept any liability whatsoever for loss or damage arising from any errors which might be contained in the documentation, text or operation of the programs supplied.

It shall be the responsibility of the customer (and not CSC)

to check the documentation, text and operation of the programs supplied,

to ensure that the person operating the programs or supervising their operation is suitably qualified and experienced,

to ensure that program operation is carried out in accordance with the user manuals,at all times paying due regard to the specification and scope of the programs and to the CSC Software Licence Agreement.

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CSC (UK) Ltd, hereinafter referred to as the OWNER, retains all proprietary rights with respect to this program package, consisting of all handbooks, drills, programs recorded on CD and all related materials. This program package has been provided pursuant to an agreement containing restrictions on its use.

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This confidentiality of the proprietary information and trade secrets of the OWNER shall be construed in accordance with and enforced under the laws of the United Kingdom.

Fastrak documentation: Fastrak software: CSC (UK) Ltd 2012 CSC (UK) Ltd 2012All rights reserved. All rights reserved.

Trademarks Fastrak is a trademark of CSC (UK) LtdTEDDS is a registered trademark of CSC (UK) LtdOrion is a trademark of CSC (UK) LtdThe CSC logo is a trademark of CSC (UK) Ltd

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DisclaimerFriday 4 January 2013 15:52

Table of Contents Connections Documentation page 5Help System Overview . . . . . . . . . . . . . . . . 8Customising Connections . . . . . . . . . . . . . 8

How do I set preferences? . . . . . . . . . . . . . 8How do I control Connections interface components? . . . . . . . . 8

Working with Projects . . . . . . . . . . . . . . 10How do I create a new project? . . . . . . . . . . . . 10How do I open an existing project? . . . . . . . . . . . 11How do I close a project? . . . . . . . . . . . . . 11How do I save a project with the same file name? . . . . . . . . . 11How do I save a project with a new file name? . . . . . . . . . 12How do I edit the project details? . . . . . . . . . . . 12

Working with Connections . . . . . . . . . . . . . 12How do I add a new connection to a project? . . . . . . . . . 12How do I add a new connection of the same type to a project?. . . . . . . 13How do I modify the reference details for a connection? . . . . . . . . 13How do I modify the configuration of a connection? . . . . . . . . 13How do I copy a connection? . . . . . . . . . . . . 14How do I delete a connection? . . . . . . . . . . . . 14How do I edit the basic connection details? . . . . . . . . . . 15How do I perform the design? . . . . . . . . . . . . 15How do I view a designs results? . . . . . . . . . . . 15

Working with Views . . . . . . . . . . . . . . 15How do I control the view in the connection Definition window? . . . . . . 15

Working with Reports . . . . . . . . . . . . . . 17How do I set up a page header or page footer? . . . . . . . . . 17How do I set up a report page? . . . . . . . . . . . . 20How do I control the contents of a report? . . . . . . . . . . 20How do I view a report? . . . . . . . . . . . . . 20How do I export a report to Microsoft Word?. . . . . . . . . . 21How do I export a report to a pdf file? . . . . . . . . . . . 21How do I print a report? . . . . . . . . . . . . . 22How do preview a report? . . . . . . . . . . . . . 22How do I control the printer used to create a report? . . . . . . . . 22

Exporting information from Fastrak Connections . . . . . . . . . 22How do I return information to the Building Designer? . . . . . . . . 22

Connections Documentation page 6 Table of ContentsBS5950 Connections Design Handbook

Connection Modelling in Building Designer 26Introduction . . . . . . . . . . . . . . . . 26Data Sources . . . . . . . . . . . . . . . 26Connection Types . . . . . . . . . . . . . . . 26Generating Connections . . . . . . . . . . . . . 28Editing Connections . . . . . . . . . . . . . . 29Viewing Results and Creating Output . . . . . . . . . . . 29

Simple Connections 30Scope . . . . . . . . . . . . . . . . . 30

Connection Types . . . . . . . . . . . . . . 30Steel Grades . . . . . . . . . . . . . . . 31Notches . . . . . . . . . . . . . . . . 31Connecting Element Geometry . . . . . . . . . . . . 32Bolts . . . . . . . . . . . . . . . . 32Design Forces . . . . . . . . . . . . . . . 32Tie forces . . . . . . . . . . . . . . . . 32

Limitations and Assumptions . . . . . . . . . . . . . 32General Limitations . . . . . . . . . . . . . . 32General Assumptions . . . . . . . . . . . . . . 33Additional Assumptions and Limitations for Toe Plate Connections . . . . . . 35

Design Checks . . . . . . . . . . . . . . . 36

Moment Connections 38Scope . . . . . . . . . . . . . . . . . 38

Connection Types . . . . . . . . . . . . . . 38Steel Grades . . . . . . . . . . . . . . . 38End Plates. . . . . . . . . . . . . . . . 38Bolts and Welds . . . . . . . . . . . . . . . 39Stiffeners . . . . . . . . . . . . . . . . 39Design Forces . . . . . . . . . . . . . . . 40

Limitations and Assumptions . . . . . . . . . . . . . 40Limitations . . . . . . . . . . . . . . . 40Assumptions . . . . . . . . . . . . . . . 41

Design Checks . . . . . . . . . . . . . . . 42

Column Splices 46Scope . . . . . . . . . . . . . . . . . 46Limitations and Assumptions . . . . . . . . . . . . . 46

Limitations . . . . . . . . . . . . . . . 46Assumptions . . . . . . . . . . . . . . . 47

Hollow Section Connections 48Practical Applications . . . . . . . . . . . . . . 48

Checking a Hollow Section Connection . . . . . . . . . . . 48Scope . . . . . . . . . . . . . . . . . 49

Connection configurations . . . . . . . . . . . . . 50Steel sections . . . . . . . . . . . . . . . 50

Theory and Assumptions . . . . . . . . . . . . . 50Friday 4 January 2013 15:56

Table of Contents Connections Documentation page 7Design . . . . . . . . . . . . . . . . 50

Column Bases 51Limitations and Assumptions . . . . . . . . . . . . 51

General Limitations and Assumptions . . . . . . . . . . . 51Limitations and Assumptions specific to Simple Bases . . . . . . . . 53Limitations and Assumptions specific to Moment Bases . . . . . . . . 53

Analysis 57Global analysis . . . . . . . . . . . . . . . 57Connection analysis . . . . . . . . . . . . . . 57

Additional Design Considerations 58Accidental Limit state . . . . . . . . . . . . . . 58

Structural Integrity . . . . . . . . . . . . . . 58Fire Limit State . . . . . . . . . . . . . . 59

Serviceability Limit State . . . . . . . . . . . . . 59

Sign Conventions 60Simple Connections . . . . . . . . . . . . . . 60Moment Connections . . . . . . . . . . . . . 60Column Bases . . . . . . . . . . . . . . . 60Hollow Section Connection . . . . . . . . . . . . 60

References 61Simple Connections . . . . . . . . . . . . . . 61Moment Connections . . . . . . . . . . . . . . 61Hollow Section Connections . . . . . . . . . . . . 61Column Base Connections . . . . . . . . . . . . . 61

Connections Documentation page 8 Chapter 1 : Working With Fastrak ConnectionsHelp System

Chapter 1 Working With Fastrak Connections

Overview

The main sections in this document are listed below. The links take you to the initial topic for that section.

Major topics Overview Customising Connections Working with Projects Working with Connections Working with Views Working with Reports Exporting information from Fastrak Connections

Customising ConnectionsThese topics tell you how to customise the Fastrak Connections interface, both by preferences which you can set, and also by the components you can add-to, or remove-from the interface.

The links below detail all the available topics in this section.

Related topics How do I set preferences? How do I control Connections interface components?

How do I set preferences?

1. Pick File/Preferences

2. Use the various pages of the Preferences property sheet to tailor the way that you and Connections work together.

How do I control Connections interface components?You can switch various elements of the Fastrak Connections interface on and off at will.

When you install Fastrak Connections the toolbars, status bar, workbook and project workspace are all shown. We would recommend that you do not turn these off on a long term basis since they provide much useful information and are the quickest way to access many features. However, you may want to switch one or more off momentarily to increase the area available for a graphical display.

Chapter 1 : Working With Fastrak Connections Connections Documentation page 9To hide a toolbar

1. Pick View/ToolbarsToolbar Name (where Toolbar Name is the name of the toolbar you want to switch off).

Note Toolbars which are already switched off will not have the icon against their name in the list.

To show a toolbar

1. Pick View/ToolbarsToolbar Name (where Toolbar Name is the name of the toolbar you want to switch on).

Note Toolbars which are already switched on will have the icon against their name in the list.

To set the position of a toolbar

1. Grab the toolbar by its handle (a vertical bar to its left for a horizontal toolbar, or a horizontal bar at its top for a vertical toolbar) and drag the toolbar to its new location.

2. If you place the toolbar over an edge of the main Connections window, then it will dock to that edge.

To change the shape of a floating toolbar

In order to change the shape of a toolbar it must not be docked against an edge of the Connections window.

1. Position the cursor over an edge of the floating toolbar, and you will see that the pointer changes to a representation of two arrows.

2. Click and hold the left mouse button and drag in the direction of the arrows.

3. The toolbar will change shape in a series of steps, to accommodate the buttons that it contains. Once you have achieved the shape that you require release the mouse button.

To hide the status bar

1. Pick View/Status Bar.

Note If the status bar is already switched off it will not have the icon against its name in the menu.

To show the status bar

1. Pick View/Status Bar.

Note If the status bar is already switched on it will have the icon against its name in the menu.

To hide the workbook

1. Pick View/Workbook.

Connections Documentation page 10 Chapter 1 : Working With Fastrak ConnectionsNote If the workbook is already switched off it will not have the icon against its name in the menu.

To show the workbook

1. Pick View/Workbook.

Note If the workbook is already switched on it will have the icon against its name in the menu.

To hide the project workspace

1. Pick View/Project Workspace or click the icon at the top-right of the project workspace.

Note If the project workspace is already switched off it will not have the icon against its name in the menu.

To show the project workspace

1. Pick View/Project Workspace.

Note If the project workspace is already switched on it will have the icon against its name in the menu.

To set the position of the project workspace

1. Grab the project workspace by its handle (the title bar at the top of the project workspace pane) and drag it to its new location.

2. If you place the project workspace over an edge of the main Connections window, then it will dock to that edge.

Working with Projects

These topics relate to the way in which you can work with projects in Fastrak Connections.


Related topics How do I create a new project? How do I open an existing project? How do I close a project? How do I save a project with the same file name? How do I save a project with a new file name? How do I edit the project details?

How do I create a new project?

1. Pick File/New Project ( ).

Chapter 1 : Working With Fastrak Connections Connections Documentation page 112. Enter the Project Details (the Job No. is required, the other information is optional) and then click OK.

3. Pick the Type of the first connection that your project is to contain and enter its Reference. Once you have done this click OK.

4. You will see a dialog which allows you to define the detail of the connection. Use its various pages to do so and then click OK.

5. Your new project opens and you will see the Connection Definition window for the first connection it contains.

How do I open an existing project?

1. Pick File/Open Project ( ).

2. Navigate to the folder which contains the project you want to open, then either: click the file name, and then click Open, or double click the file name.

How do I close a project?

1. Pick File/Close

2. If the project has not changed in any way since you last saved it, then it will close immediately.

3. If the project has changed, then you will be asked if you want to save it. The options you have are:

Yes save the project1 and then close it, No close the project losing any unsaved changes, Cancel abort the closing of the project, leaving it open.

How do I save a project with the same file name?

1. Pick File/Save ( ).

2. If you havent saved the project before, then you will see the Save As dialog.

a) Use this dialog to navigate to the folder into which you want to save the project, enter the File name you want to use for the project and then click Save.

3. If you have saved the project before, then this option simply updates the saved file to take account of any changes.

Footnotes1. If you have never saved the project, then Connections will allow you to specify the folder and file name under

which it is to be saved. If you have saved the project previously (so that it has a folder and file name), then Connections will automatically save the project under the existing path and file name.

Connections Documentation page 12 Chapter 1 : Working With Fastrak ConnectionsHow do I save a project with a new file name?

1. Pick File/Save As You will see the Save As dialog which automatically shows the folder and file name under which the project is currently saved.

2. If necessary navigate to the folder into which you want to save the project and/or enter the new File name you want to use for the project and then click Save.

How do I edit the project details?

You set the initial project details as you create a new project. If you want to change these later, this is easily done. 1. Pick File/Project Details and you will see the Project Details dialog together with the

current information which is defined for this project.

2. Make any changes that are necessary, and then click OK to close the dialog.

Working with Connections


Related topics How do I add a new connection to a project? How do I add a new connection of the same type to a project? How do I modify the reference details for a connection? How do I modify the configuration of a connection? How do I copy a connection? How do I delete a connection? How do I edit the basic connection details? How do I perform the design? How do I view a designs results?

How do I add a new connection to a project?

1. Pick Connection/New Connection to see the New Connection dialog.

2. In this dialog choose the type of connection that you want to create, enter the Reference details of the connection and then click OK.


4. A new window will be added to your project showing your new connection, and a corresponding entry will be added to the Project Workspace.

Chapter 1 : Working With Fastrak Connections Connections Documentation page 13How do I add a new connection of the same type to a project?Fastrak Connections assumes that the projects you create will contain more than one of any particular type of connection. Once you have created a new connection, you can create more connections of the same type instantly.

1. Pick Connection/New xxx1 Connection or click the icon for the connection type from the Connections toolbar.

Note The icon in the toolbar changes to show that relating to the type of connection you last created. These are detailed below.


3. A new window will be added to your project showing your new connection, and a corresponding entry will be added to the Project Workspace.

How do I modify the reference details for a connection?

1. There are two methods which you can use to change the connection reference: a. Ensure that a window relating to the connection whose reference you want to change

is active and then pick Connection/Reference ( ) b. Right click over the reference that you want to change in the Project Workspace and

then pick Reference from the context menu.

2. Enter the amended Reference details for the connection and click OK.

How do I modify the configuration of a connection?

1. There are two methods which you can use to change the connection configuration:

Footnotes1. Where xxx is the type of the connection you last created.

Icon Connection typeBeam-column moment connection

Beam-beam moment connection

Column base connection

Beam-column simple connection

Beam-beam simple connection

Connections Documentation page 14 Chapter 1 : Working With Fastrak Connectionsa. Ensure that a window relating to the connection whose reference you want to change is active and then pick Connection/Edit Connection You can also pick the appropriate icon from the toolbar.

Note The icon in the toolbar changes to show that relating to the current type of connection. These are detailed below.

b. Right click over the reference of the connection whose configuration you want to change in the Project Workspace and then pick Edit Connection from the context menu.

2. You will see the Connection Configuration dialog appropriate to this type of connection. Make the changes that you require and then click OK.

How do I copy a connection?

1. There are two methods which you can use to create a copy of an existing connection: a. Make sure that the connection you want to copy is the active one, and then click

Connection/Copy from the menu.b. Right click the column reference in the project workspace and then choose Copy from

the context menu.

How do I delete a connection?

1. There are two methods which you can use to delete a connection: a. Make sure that the connection you want to delete is the active one, and then click

Connection/Delete from the menu.b. Right click the column reference in the project workspace and then choose Delete

from the context menu.

Icon Connection typeBeam-column moment connection

Beam-beam moment connection

Column base connection

Beam-column simple connection

Beam-beam simple connection

Chapter 1 : Working With Fastrak Connections Connections Documentation page 15How do I edit the basic connection details?

1. Right click the connection reference in the project workspace and then choose Edit Connection from the context menu.

2. Use the various pages of the Connection Properties sheet to change the connections details, then click OK to set them.

How do I perform the design?

1. Pick Connection/Check Connection ( ) and you will see the results immediately.

How do I view a designs results?

1. Pick Connection/Check Connection ( ).

2. If the design is current (that is nothing has changed since the last design), then you will see the results immediately.

3. If the design is not current then it will be performed while you wait (which in practice means that you will see the results immediately on most modern systems).

Working with Views

The topics relate to the ways in which you can control views of your connections in Connections.


Related topics How do I control the view in the connection Definition window?

How do I control the view in the connection Definition window?

Fastrak Connections provides a whole range of options which allow you to control the view in the Connection Definition window. You can use a range of standard views, or you can rotate the view to any orientation you require. You can also zoom and pan the view so that you can see just what you need. You can navigate through the most recent views you have defined quickly and easily.

To use a standard view

1. Simply use one of the methods below to choose the standard view that you want to see. a. Pick View/OptionsView Name (where View Name is the name of the standard view

you want to see).

Connections Documentation page 16 Chapter 1 : Working With Fastrak Connectionsb. Click the appropriate icon from the Connection Details View toolbar.

To rotate the view

If none of these standard views is appropriate, then you can rotate the connection to get to just the view you require.

1. Simply right-click and hold over the connection in the Connection Definition window, and move the mouse to perform the rotation.

2. Once you have achieved the view you require simply release the mouse button.

To zoom into an area

1. Pick View/OptionsZoom Area.

2. Move the mouse pointer over one corner of the area into which you want to zoom.

3. Click and hold the left mouse button and drag to the diametrically opposite corner of the same area.

4. Release the mouse button and the display will zoom to show this area.

To zoom on the display centre

1. Click and hold both mouse buttons.

2. Move the mouse pointer down to zoom in-to the centre of the display or up to zoom out-from it.

3. Alternatively if you have a mouse with a wheel you can rotate the wheel to zoom in or out on the centre of the display.

Icon View from:Front

Top

Left

Back

Bottom

Right

South-West

South-East

North-East

North-West

Chapter 1 : Working With Fastrak Connections Connections Documentation page 17To pan the view?

1. Simply click and hold the middle mouse button or mouse wheel 1over the Connection Definition window, and move the mouse to pan the display.

2. Once you can see the part of the view that you require simply release the mouse button.

To navigate through views

1. Simply use the buttons of the View toolbar to navigate through the views you have defined in the Connection Definition window.

Note These buttons perform different functions in the Report window.

Working with Reports

Once you have defined your connections you can create a wide range of reports, many of which you can tailor extensively to meet your, or your customers, specific requirements.


Related topics How do I set up a page header or page footer? How do I set up a report page? How do I control the contents of a report? How do I view a report? How do I export a report to a pdf file? How do I export a report to Microsoft Word? How do I print a report? How do preview a report?

How do I set up a page header or page footer?The header and footer are tables which appear at the top and bottom respectively of every page of your report. You can define the number of rows and columns in the tables, the widths of the column, and you can also merge cells to increase the available size, for instance to accommodate your company logo.

Footnotes1. You must have a mouse with a middle button or wheel to use this option.

Icon ActionShow the first available view

Show the previous view

Show the next view

Show the last available view

Connections Documentation page 18 Chapter 1 : Working With Fastrak ConnectionsOnce your table layout is complete you can determine which information appears in each cell, and define the appropriate details.

1. Pick File/Report View SetupReport Define Header and you will see the Edit Header Layout dialog, or pick File/Report View Setup Report Define Footer and you will see the Edit Footer Layout dialog.

2. Once your settings are complete click OK to close the dialog.

How do I set the horizontal alignment of a cell?1. Right click the cell in the table.

Note The current alignment setting for the cell is shown below the table.

2. Pick Horizontal Alignment/Left, Horizontal Alignment/Right, or Horizontal Alignment/Centre from the context menu that appears.

3. The cell in the table shows the new alignment.

How do I set the vertical alignment of a cell?1. Right click the cell in the table.

Note The current alignment setting for the cell is shown below the table.

2. Pick Vertical Alignment/Top, Vertical Alignment/Bottom, or Vertical Alignment/ Centre from the context menu that appears.

3. The cell in the table shows the new alignment.

How do I join cells?1. Left click and hold over the top left most cell that you want to join.

2. Drag down and to the right and you will see a rectangle that follows the mouse pointer.

3. When the rectangle encompasses the cells that you want to join release the mouse button.

Note The lines between the cells are removed, however the cell field names are maintained. However when cells are joined it is only the information referred to by the top left hand most field that is displayed in the header.

How do I unjoin cells?1. You can rejoin cells in a different combination as detailed above.

2. Alternatively you can right click over the top left hand most field name in the group of joined cells and then pick Unjoin from the context menu that appears.

How do I add a row?1. Click Add a row to add a row to the bottom of your table.

How do I add a column?1. Click Add a column to add a column to the right of your table.

Chapter 1 : Working With Fastrak Connections Connections Documentation page 19How do I delete a row?1. Right click over the row that you want to delete.

2. Pick Delete row from the context menu that appears.

How do I delete a column?1. Right click over the column that you want to delete.

2. Pick Delete column from the context menu that appears.

How do I set the column width?1. Click Columns and you will see the Column Widths dialog.

2. Pick the column whose width you want to set, and then define the appropriate details in the fields at the bottom of the dialog. The options are as follows:

Fixed The width of the column is fixed at the value you specify, the options are:

Percent The column takes up the specified percentage of the total page width.

mm The column is the specified number of millimetres wide. If you use this option, then you must ensure that the total column widths fit within the printable area of the page.

Residual The column takes up the remaining width not required by the other columns in the table. You can only define one column which has its Type set to Residual.

How do I determine which information shows in which cell?1. Click on the variable that you want to place in the cell from the list of Fields.

2. Click on the field to set the field to show that variables name.

Note When cells are joined it is only the information referred to by the top left hand most variable name that is displayed in the header.

How do I define the information for a variable?1. Click Edit fields to see the Edit Fields dialog.

2. Pick the field from the list of the Available Fields, and then define the appropriate data in the Field Settings part of the dialog.

How do I add a new variable or delete one that I previously added but no longer require?1. Click Add/Remove fields

2. To add a new field type in the field name that you want to use (this must be different from any existing field name), and then click Add.

3. To delete a field that you dont require pick the field from the list of Available Fields, and then click Remove.

Connections Documentation page 20 Chapter 1 : Working With Fastrak ConnectionsHow do I set up a report page?

1. Pick File/Report View SetupReport Print Options and you will see the Report Settings dialog.

2. Use the various pages of this dialog to set the fonts for the various paragraph styles used in the report, to set the margins you want to use and the options that you want to use for the tables within your report.

3. Once your settings are complete click OK to close the dialog.

How do I control the contents of a report?

1. Pick File/Report Contents ( ) and you will see the Report Content dialog. This allows you to control the content of your report for each connection in your project as detailed below.

Included If you check this item, then this connection will be included in the report. If you dont check this item, then the connection in its entirety will be excluded from the report irrespective of the other settings on the line.

Diagram Check this item to include a diagram of the connection in the report, uncheck it and the diagram will not be included.

Summary If you check this item, then the connection design status information will be included in the report. This simply tells you which is the critical combination for the design (that with the worst utilisation ratio for any check.

Basic Details This option allows you to control the reporting of the basic connection details. These include (among other things) the details of the section size(s), cleat details, end-plate details These obviously depend on the type of connection.

Report Level This setting allows you to control the amount of information that you wish to include in your report on the design for the connection. These range from None to Full, and progressively include more information about the design.

2. Once you have made your settings click OK to create and see the report.

How do I view a report?

1. Once you have defined the content of the report it will be automatically created for you. If you have closed the report window, and you want to view the report again, then pick File/Report Connection Items ( ) and the report will be generated and shown on your screen. You can tailor the way in which the report is shown to achieve a result which enables you to best view the details you require.

2. Once you can see the report you can choose to export it to TEDDS, export it to Microsoft Word, or print it to produce a hard copy.

Chapter 1 : Working With Fastrak Connections Connections Documentation page 21To navigate through a report

1. You can navigate through the report by using the buttons of the View toolbar.

Note These buttons perform different functions in the connection Definition window.

How do I export a report to Microsoft Word?

1. Set up your report so that it contains the information you require.

2. Pick File/Export report to Word ( ). Word will open and you will see a dialog which allows you to control the formatting of the report. Make the settings that you require, and then click OK.

Note At this point, if your report runs to many pages, you may see the message Because there is a large amount of input data, the document must be saved periodically during the import process. If you do not wish to save the document select Cancel. If you click OK, then you should immediately see the Word Save As dialog so that you can specify the name under which the file will be saved. Sometimes you will not see this dialog, and after a short delay you will see a Server Busy dialog instead! Dont panic, this just means that Word is waiting for you to give the file name, its just that you cant see the Save As dialog as it is hidden by another window. Simply click Switch to to bring Word to the front of all other windows, you will then be able to see the Save As dialog. Now enter the file name and click OK to continue with the export process. This is a known issue with Word.

3. After a delay while the export process completes you will see the report in Word.

How do I export a report to a pdf file?


2. Pick File/Export report to PDF. The report will be created immediately, and you will see a dialog asking if you want to view the file.

3. If you do click Yes.

Icon ActionShow the first page of the report

Show the previous page of the report

Show the next page of the report

Show the last page of the report

Connections Documentation page 22 Chapter 1 : Working With Fastrak ConnectionsHow do I print a report?


2. Pick File/Print ( ). You will see your systems normal Print dialog.

3. Make the settings you require and then click OK.

How do preview a report?

1. Pick File/Print Preview and you will see a preview of your report.

How do I control the printer used to create a report?

1. Pick File/Print Setup you will see your systems normal Print Setup dialog.

2. Make the settings you require and then click OK.

Exporting information from Fastrak Connections

The topics below relate to exporting information from Fastrak Connections.


Related topics How do I return information to the Building Designer?

How do I return information to the Building Designer?

This option is only available when you have defined a connection in Building Designer, and transferred it from there into Fastrak Connections in order to work on it.

1. Manipulate the design in Fastrak Connections until you have achieved a result with which you are satisfied.

2. Pick Connection/Return Connection to Building Designer to return the connections details back to that application.

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Connections Documentation page 24

Chapter 2 : Introduction Connections Documentation page 25BS5950 Connections Design Handbook

Chapter 2 Introduction

This Engineers Handbook describes your BS5950 Fastrak Connections application. This is design software which allows you to design simple, moment, hollow section and column base connections.

Simple Connections transfer vertical shear only,

Moment Connections transfer vertical shear and major axis moment,

Column Splices continuity splices in simple construction,

Hollow Section Connections 1 welded hollow section connections of certain configurations including connections with I or H section chords. principally for use in truss work,

Column Bases simple and moment resisting bases including soil bearing pressure and concrete base design.

Unless otherwise stated all calculations are in accordance with the relevant sections of BS 5950-1: 2000 and the design models for connections draw heavily on the series of publications from the Steel Construction Institute that cover the design of connections the so-called Green Books.(Ref. 1),(Ref. 2)

All Hollow Section Connection calculations are in accordance with the relevant sections of BS EN 1993-1-8:2005 with the exception of those connection configurations that are not covered by this publication {see the Theory and Assumptions Chapter for more details}. You may find the references quoted later in this document a useful source of information.

The following advice is written principally from the point of view of operating connection design from within Building Designer. Where necessary any important factors with regard to the operation of the stand alone application are noted.

Footnotes1. For the current release there is no integration between the hollow section connections and the Building Designer

model.

Connections Documentation page 26 Chapter 3 : Connection Modelling in Building DesignerChapter 3 Connection Modelling in Building Designer

IntroductionThe definition and check of connections is an intrinsic part of Fastrak Building Designer all data associated with a particular connection is held within the building model. All connections can be opened within Building Designer where they can be modified and refined before saving the data back to the model. Alternatively one or many connections can be passed out to Fastrak Connections where, again, they can be modified and refined and then passed back to Building Designer. Note that certain details (for example the section sizes of the connecting members) cannot be modified since this would affect other parts of the building model. As a further alternative Fastrak Connections can be run as a stand-alone application and the connection data entered in isolation.

Data SourcesWhilst all connection data is held in the building model, the source of such data is several fold. This includes,

attributescertain data can be set to be used during the definition of the connections e.g. beam to beam simple connections are to be fin plates,

derived datathe building model already holds such items as the section size and grade of the members that are that are to be connected and the design forces,

default datawhen the connections within the building model are set up by Fastrak, intelligent defaults are used that can establish a part or full solution to the connection configuration,

added dataany individual connection can be edited to improve or add to the connection configuration e.g. stiffeners can be added to moment connections.

Connection Types

Simple ConnectionBuilding Designer will attempt to configure a simple connection at the end of any Simple Beam, Composite Beam or General Beam that is pinned. The word attempt is used since there are some configurations of member and connection that are beyond the scope of the current release, for example, if the supporting beam is not an I-section or the supported beam frames in at a steep angle.

Chapter 3 : Connection Modelling in Building Designer Connections Documentation page 27Simple connections can be end plates, fin plates and (double) angle cleats. During definition of your building model a set of Connections Attributes can be established such that by preference, for example, beam to column web connections are end plates and are designed for the minimum tie force requirement of 75 kN. The defaults for these attributes are:

beam to beam - fin plate with one line of bolts, beam to column flange - end plate, beam to column web - end plate, beam to hollow section column -fin plate.1

When a particular type of connection is established by Building Designer in the model, for example, a fin plate for beam to beam connections, the default settings for bolt size and number, fin plate thickness and so on, are such that the subsequent check of this connection should under normal circumstances give a Pass. This happens because simple connections are more about detailing than design, that is a well detailed simple connection will usually be adequate in design. This has been underpinned in Building Designer by careful selection of the defaults to ensure that the Recommended Details and standard connections contained in the Green Book on simple connections (SCI P212)(Ref. 1) are followed.

This all means that as a designer, once you have selected the type of connecting element for a particular situation, for example a fin plate for beam to beam connections, Building Designer will provide robust and well detailed simple connections for the majority of the building. It is likely then that only a few connections will not be adequate. These can be displayed to you on the main building graphic and you can then interactively adjust the connection type or configuration to establish an adequate detail. Examples of connections where you need to make such changes might be:

a heavily loaded beam that might require two lines of bolts, or a shallow beam where the default bolt pitch has to be decreased in order to increase the

number of bolts.

Moment ConnectionBuilding Designer will attempt to configure a moment connection at the end of any General Beam that has a Moment Connection or is fully fixed at the appropriate end. The word attempt is used since there are some configurations of member and connection that are beyond the scope of the current release e.g. if the supporting column is not an I or H-section or the supported beam frames into another beam.

Moment connections can be established at beam to I- and H-section column flanges, and at beam to beam on end e.g. apex type connections. All are formed using bolted end plates in the current release. Beam to column moment connections can be single- or double-sided.

There are no Connections Attributes associated with moment connections in Building Designer. Hence, during definition of your building model only the essential data and a number of basic defaults are set up for each moment connection. Essential data includes section size of the members joined and their design forces. Basic defaults include such items as

Footnotes1. In the current release end plates and angle cleats are prohibited from use with hollow sections.

Connections Documentation page 28 Chapter 3 : Connection Modelling in Building Designerone pair of M20 Grade 8.8 bolts top and bottom of the connection with 20 mm thick end plates. It is necessary therefore for you to 'open' each individual connection and enter such data as,

additional tension and shear bolts, extensions to the end plate, stiffeners, haunches.

Obviously at the same time you can also adjust the default values e.g. change from 20 mm thick end plate to 25 mm thick.

Column SpliceBuilding Designer will attempt to configure a column splice at the end of any Simple Column where a splice position has been specified in the Floors tab of the Column Properties dialog. The word attempt is used since there are some configurations of member and connection that are beyond the scope of the current release, for example, if the column section is not an I-section or if the column is specified as a General Column.

There are two types of column splice: bearing splice - load is transferred in bearing directly or through a division plate, non-bearing splice - load is transferred through the bolts and splice plates.

Bearing splices being simpler are generally preferred, particularly for heavily loaded connections. In Building Designer this type is therefore the default.

As with simple connections, default settings for bolt size and number, plate thickness and so on, are chosen such that the subsequent check of this connection should under normal circumstances give a Pass.

Hollow Section ConnectionBuilding Designer will not configure any hollow section connections in the current release. Hollow section connections can therefore only be checked when running Fastrak Connections as a stand-alone application.

Column BaseBuilding Designer will attempt to configure a column base at the lower end of any Simple Column or General Column at any level where a support has been defined in the model.

Generating ConnectionsOnce the building model has been designed, you can click on the Update Connections icon. This will create and load all the connections in the model and display them in the Connections-3D window.

Chapter 3 : Connection Modelling in Building Designer Connections Documentation page 29Editing Connections

You may prefer to adjust the connections inside Building Designer or you can send one or more connections to the stand-alone application. In either case the data you have added or modified is saved in Building Designer. You can see whether your connection configuration looks sensible by right clicking on the connection in the Connections window - this displays a 3D graphic of the connection in its own window. You can adjust each of the connections individually and design them as you proceed or once you are content with the layout of all of them you can click the Check Connections icon. You can use the Show/Alter State icon to view which have passed and which have not.

Viewing Results and Creating Output

Results of your connection design can be viewed on the screen. The input, diagrams, and design results can be incorporated into a report by sending the connection or selection of connections out to Fastrak Connections. From there you can control exactly what you wish to see in the report.

Connection components for example bolts, welds, stiffeners are not listed in the Material Listing report.

Connections Documentation page 30 Chapter 4 : Simple ConnectionsChapter 4 Simple Connections

ScopeSimple connections are by definition pinned connections and transfer vertical shear only.

Connection TypesFor design to BS 5950, simple connections can be one of four types end plate, fin plate (double) angle cleat or toe plate. These are termed connecting elements. In the case of fin plates and the leg of the angle cleat to the supported beam, a double line of bolts can be specified. Any of these connecting elements can be provided for beam to beam, beam to column flange and beam to column web connections provided that both the supported beam and the supporting column or beam is an I- or H-section. In the current release, only fin plates can be used to connect to hollow section columns.

Toe Plate ConnectionsA Toe Plate connection comprises:

a partial or full depth flexible end plate welded to the end of the supported beam a pre-formed fitting comprising a fin plate welded with a full strength weld to a further

flexible end plate (the toe plate) the pre-formed fitting is then welded in place with a full strength weld to the supporting

beam web with placement welds to the i/s face of the flanges the connection can be single sided or can be on both sides of the supporting beam.

To keep the connection parameters within the scope of the simple connection design philosophy, the component parts are chosen so as to comply with the recommendations given in the Green Book on simple connections (SCI P212).(Ref. 1)

The design model for the Fin Plate is based on that given in SCI P212.

Chapter 4 : Simple Connections Connections Documentation page 31The design model for the Flexible End Plate and the Toe Plate is based on that given in SCI P212.

Steel GradesSupporting and supported members and their connecting elements are limited to S275 and S355 grade steels there are a number of semi-empirical rules in the design models that preclude the use of S460 grade steels.

NotchesFor beam to beam connections a notch length can be defined that suits the width of the supporting beam flange this must be the same on both sides of the supporting beam. For each side a notch depth at the top and bottom of the supported beam can be defined these can be different top and bottom and, different on each side. For convenience standard notch lengths and depths are defaulted and via the Set Standard Notches button you can recover these if you have changed something but wish to get back to the standard values1. Notch details also appear on beam to column connections but changing the default values from zero has no effect.

To avoid notching in beam to beam connections a fin plate can be selected to ensure that the supported beam and the fin plate are joined outside of the flanges of the supporting beam. This will usually create a long fin plate for which certain additional checks are required and are carried out by Fastrak Connections.

Footnotes1. Note that in the stand-alone application if you change the notch details and subsequently change the details of

the connection, for example the section size, the default notch length and depth are reinstated.

Connections Documentation page 32 Chapter 4 : Simple ConnectionsConnecting Element GeometryConnecting elements can be of different types on each face of the supporting beam or column although those either side of a beam or column web have some design restrictions see Design Checks. Beams can frame in at different levels or can be aligned (in beam-to-beam connections) with the top flange, bottom flange or centre line of the co-joined members.

BoltsA wide range of bolt grades and sizes can be defined and, by default, their layout (end and edge distance, pitch and gauge) meet the Recommended detailing practice given in SCI P212 (Check 1). The number of bolts is defaulted to meet the standard connections contained therein. Similarly, weld sizes for use with fin plates and end plates are the standard values. For angle cleats the default bolt layout is the same in both legs but you can select different layouts in each leg if required. You are able to adjust all these defaults but you are advised to do so with care.

Design ForcesThe design forces for simple connections are shear in the plane of the web of the supported beam and where appropriate tie forces. A set of these can exist for each design combination and these are established from the analysis of the building model as a whole (or entered independently in the stand alone application). You can edit the design forces, delete and add load combinations and these changes will be reflected in the design of the connection immediately following the changes. However, all these changes will be lost if you subsequently use the Update Connections function in Building Designer.

Tie forces Tie forces must be considered in the design. For details of how these forces are calculated refer to the later section Accidental Limit state

Limitations and Assumptions

General LimitationsThe following limitations apply:

single angle cleat as connecting elements are excluded, a double line of bolts in end plates and in the leg of an angle cleat to the supporting

member are excluded, in a beam to column web connection where the supported beam flange is wider that the

internal dimension between the flanges of the supporting column, in practice a flange strip would normally be called for. Such flange strips are not included in the current release and so you must judge whether they might influence the results from Fastrak,

similarly where the bottom flange of a beam on one side of a connection might interfere with the bolts on the other (deeper) side of a connection a snipe or flange strip is often used in practice. Such snipes and flange strips are not included in the current release and so you must judge whether they might influence the results from Fastrak,

channel section and hollow section beams are excluded, plated section beams, Westok beams and Fabsec beams are excluded,

Chapter 4 : Simple Connections Connections Documentation page 33 sections with unequal flanges are excluded. This covers not only plated section beams that have unequal flanges but also Slimflor beams and asymmetric Slimflor beams,

connections to concrete filled hollow section columns are excluded, where more than one beam connects to the face of the supporting member, Building

Designer cannot form the connection.

Where a component is excluded, for example channel section beams, Building Designer will not create a connection to that beam. In addition, where a connection would otherwise be created on one face of the supporting member but on another side a connection cannot be created then no connection at all will be created. For example, no connection will be created in the case where a channel section edge beam connects to a column on one face and an I-section connects to another face.

General AssumptionsEssentially the assumptions in Fastrak Connections are those inherent in the design models for simple connections given in SCI P212(Ref. 1). However, a number of specific assumptions are made as given below.

Internal forces in the supporting member from the applied loading that it carries are assumed not to influence the connection design. For example, the axial force in a column from floors above is assumed not to affect significantly the performance or behaviour of the connection.

Similarly, where simple connections and moment connections are connected to the same column it is assumed that the forces imparted by the one do not influence the other. A typical example might be moment connections to the column flanges with simple connections to the column web. Not only are the designs independent but also the detailing. Hence. in this example any stiffening required by the moment connections are assumed not to interfere with the simple connections framing into the web.

Any shear force out-of-plane of the beam web (minor axis shear force) is assumed not to influence the connection design. Similarly any axial force in the supported beam (other than due to tying action for structural integrity) is assumed not to be significant. In the Design Options off the Design menu in Building Designer, you can specify limits for these forces below which you believe the design will be unaffected. If Building Designer detects forces greater than these limits, the design will still proceed but the connection will be given a Warning status and the value of these forces will be given in the results. The default values for these limits are:

minor axis shear 0.5 kN, axial force 1.0 kN, major axis moment 1.0 kNm minor axis moment 0.1 kNm.

The two moment limits are included even though simple connections are modelled in the analysis as pins. This is because the analysis model is a mathematical model and as such during the back substitution process very small moments that are effectively zero from an engineering point of view may exist mathematically.

Connections Documentation page 34 Chapter 4 : Simple ConnectionsWhere connected beams are not orthogonal to the supporting member, Building Designer takes the following approach (see also Global analysis),

where all angles are less than a given lower limit, then the angles are ignored and the design proceeds as if the members do connect orthogonally,

where any angle is greater than a given upper limit, then Building Designer creates the connection but the design is not performed and the connection is given a Beyond Scope status,

where one angle lies between the upper and lower limit, then the angle is ignored, the design proceeds as if the members do connect orthogonally and the connection is given a Warning status,

where more than one angle lies between the upper and lower limit, then Building Designer creates the connection but the design is not performed and the connection is given a Beyond Scope status.

In all cases the angle can be viewed either in the design results (on the Notes page) or by editing the connection. The upper and lower limits are,

lower limit for slope, skew and rotation 0.5, upper limit for slope and skew 10, and for rotation 5.

The definitions of slope, skew and rotation are depicted in the figure below.

For beam to beam connections in Building Designer, the top flanges of the supported and supporting beam are assumed to align. However, within the building model beams can be given an alignment relative to its cardinal points the default is at the centre of the top flange. Any changes that you make to the cardinal points are not reflected in the simple connection design. For example if you set the cardinal point of a supported beam to the centroid of the section and connect this to a supporting beam with the cardinal point set as the centre of the bottom flange, the simple connection design will assume, still, that the top flanges align.

Similarly, in beam to column connections the centre lines of beams and the column are assumed to node. However, within the building model both the column and the beams can be set off-grid. Any changes you make that set beams or columns off-grid will not be reflected in the simple connection design. For example, you might offset the beams on the edge of the building towards the outer face of the column to suit cladding details. Nevertheless, the simple connection design will assume, still, that the beams and the column node on the centre lines.

Slope Skew Rotation

Chapter 4 : Simple Connections Connections Documentation page 35There are likely to be a number of positions in the building where braces connect to columns at the same position as a simple connection joining beams to the same column. The brace force is assumed to be transferred directly to the column and hence in the model has no influence on the force distribution in the connections. Similarly, the detailing of the brace end connection is assumed not to affect the configuration of the simple connections at the end of the co-joined beams.

Additional Assumptions and Limitations for Toe Plate Connections

Toe Plate Connection force transfer mechanismIn the Fastrak Toe Plate Connection model, the force transfer mechanism is taken as:

The line of shear transfer (supported beam end reaction) is taken to be at the face of the web of the supporting beam. This is equivalent to the flexible support method used in the design of fin plates.

There is no torsion in the supporting beam. The fin plate, toe plate and the end plate are all designed for the resulting moment Fv* a

where a = the distance from the face of the web to the junction between the toe plate and the end plate.

To ensure that there is sufficient rotational capacity in the connection for it to be considered as "simple", only Mode 1 failure [Complete End Plate Yielding] will be allowed. If other failure modes become critical the following parameters can be adjusted so that Mode 1 becomes the critical failure mechanism:

Bolt gauge Bolt pitch Bolt diameter Bolt end distances Toe plate/end plate thickness

All of the bolts are used in both tension and shear - there are no dedicated shear bolts. The compression zone is limited to the beam flanges with the centre of rotation taken as

the mid thickness of the thinner flange. No plate stiffeners are allowed to the toe plate or to the beam end plate since these would

be counterproductive as the model "forces" Mode 1 failure in these plates. The only stiffener allowed in the model is in the extension of an extended toe plate.

Additional Limitations for Toe Plate ConnectionsThe following limitations are imposed which are additional to those implicit in SCI P212.

The top of the top flange of the supporting beam is to be flush and level with the top of the top flange of the supported beam.

Only 2 bolts will be allowed in each row. Only one row of bolts can be placed in the toe plate extension. The toe plate, fin plate and flexible end plate are to be the same steel grade. The minimum depth of the toe plate is equal to the depth of the supporting beam + the leg

length of the weld between the outside flange of the beam and the toe plate. The minimum depth of the end plate is equal to 0.6 x the depth of the supported beam.

Connections Documentation page 36 Chapter 4 : Simple Connections The maximum depth of the supported beam that can be used is 2 x the depth of the supporting beam.

The minimum depth of the supported beam than can be used is 0.5 x the depth of the supporting beam.

The connection can only accept positive bending moments and the associated shears. The minimum bolt clearance dimension from centre-line of the bolt to the nearest steel

face that is used in the software is 1.25 x bolt hole diameter.

Design ChecksThe design checks for simple connections are given in SCI P212. To assist you, the results displayed in Fastrak are given the title of each check in P212, for example: Check 5 Supported beam capacity at notch. The design models in P212 are primarily based on standard connections meeting orthogonally with, in the case of beam to beam connections, top of steel aligned. For such connections the design models are clearly laid out in P212 and so no additional explanation is given here.

However, Fastrak Connections covers a somewhat broader spectrum and so additional points of note are given below.

For each of the connections there are Recommended Detailing Requirements in SCI P212. These are recognized as good practice and you should comply with these whenever possible. If you select an item or value that is beyond these standards, you will find that the particular entry appears orange to give you a visual warning that you are stepping outside of good practice.1

There are strict limitations on the use of fin plates both in SCI P212 and in Fastrak Connections. These relate to edge and end distance, bolt size and grade, fin plate or web thickness, minimum projection and maximum lever arm between topmost and lower-most bolts in the fin plate. These restrictions are necessary to ensure ductile behaviour and adequate rotation capacity of the connection. Both these properties are essential for a simple connection to act as a pin. Fastrak Connections allows you to contravene these when specifying the connection but will fail the connection in design.

Supported and supporting members do not always meet orthogonally the assumption in Fastrak Connections is that they do. For very small angles, these are likely to be less than the normal tolerance on layout and out-of-plumb and so can safely be ignored. For slightly larger angles, the affect on the design is likely to be only nominal and so, in most cases, might be ignored. For significant angles, assuming that nevertheless they are still orthogonal may not be sufficiently accurate and hence may be unconservative. More information on the treatment of non-orthogonal connections is given in Limitations and Assumptions.

Footnotes1. If the item or value is not acceptable or not feasible to achieve e.g. the edge distance for the bolts is less than the

minimum requirement of BS 5950-1: 2000 then the text or value appears red and you cannot exit the dialog.

Chapter 4 : Simple Connections Connections Documentation page 37Supported and supporting beams in beam to beam connection do not always align with their top flanges and across a column web beams may be at different levels. Fastrak covers such situations in one of two ways.

Where the configuration of the connection either side of a web is not achievable in practice then you are allowed to accept the data and leave the dialog but no design is possible until the discrepancy has been corrected (the offending detail will also appear red on the connection graphic). An example would be where two end plates connect either side of a column web and the bolt gauge is different each side.

Where the configuration is achievable, Fastrak will carry out the design calculations. However as mentioned earlier, since the design models in SCI P212 are based on alignment of supported beams, these calculations are extrapolations of the norm. You should therefore treat the design results of such connections with care.

Supported beams either side of a beam or column web do not have to be the same type. For angle cleat one side and end plate the other side, the supporting web is checked in the normal way. However, for fin plate to one side and end plate or angle cleat the other side, there is no rigorous design model for the connection as a whole. Hence, the supporting beam web is checked for each side of the connection independently. No account is taken of any interaction between the two different connection methods on the web resistance. Fastrak reports the relevant check twice once for each connection type (SCI P212: Check 10).

The standard end plate connections in SCI P212 are 8 mm and 10 mm thick and are welded to the web only. Full depth end plates up to 12 mm thick with a full profile weld can be treated as simple connections see SCI P212: Check 1. You can select thicker end plates and this will result in a Warning status for the connection. In all cases the design model and Fastrak do not take account in design of any weld to the beam flange.

Where a supported beam is unrestrained and is notched, this can have a significant influence on the effective length of the beam for lateral torsional buckling. This is one situation where there is a direct impact of the connection configuration on the design of the beam. This is covered by SCI P212: Check 7. In Fastrak you can specify that the beam is unrestrained. However, in the current release the calculations for this check are not implemented. Consequently, this check is always reported with a Warning status if you specify that the beam is unrestrained. You are expected to carry out your own hand calculations. If you have responsibility for the connection design but not for the member design then it is important to ensure that the designer responsible for the beam design is informed of the impact of the connection configuration on his beam design.

In the stand alone application, on the Beam Details property page there is an opportunity to enter the Length (span) of the supported beam. In the building model this value is set to zero and cannot be changed. Any value specified is used only to determine whether in the case of fin plates attached to beams deeper than 610 mm that the span/depth ratio is less than 20. This is a requirement to ensure adequate rotation capacity in fin plates attached to deep beams see SCI P212: Check 1 for fin plates. If the span/depth ratio is greater than 20 the connection will be failed in the design.

Connections Documentation page 38 Chapter 5 : Moment ConnectionsChapter 5 Moment Connections

ScopeMoment connections are by definition able to transfer moment as well as vertical shear. The design is also able to deal with axial force in the beam member if present.

Fastrak Connections checks only the strength of moment connections. Stiffness, ductility and rotation capacity can be important characteristics in some situations. Your attention is drawn to Clause 2.4.2.5 of BS 5950-1: 2000 and Section 2.5 of the Green Book on moment connections (SCI P207).(Ref. 2)

Connection TypesMoment connections can be one of three types - single-sided beam to column flange, double-sided beam to column flange and beam to beam. They are formed using bolted end plates that can be flush or extended top and/or bottom. Haunches can be defined below the supported beam and can be either,

a section cutting -cut from the same size as the beam, same size as the column or from any (valid) section that you select or,

built up from plates - a plate size (width and thickness) is required for the web and flange plates.

Where a section cutting is defined, you are provided with a button to calculate 'Max Depth' of the haunch based on the length of the haunch, slope of the beam and section size selected for the haunch.

In beam to column moment connections the column and the individual beams can be assigned a 'level' within the connection application. This is not reflected in the building model.

Steel GradesColumns, beams and end plates that make up you connection can be S275, S355 and S460 grade steels. Care should be exercised when selecting S460 grade steel since the original Green Book on moment connection design (SCI P207) was written with S275 and S355 steel in mind and there may be limited availability of plate in this grade.

End PlatesA range of standard width and thickness of plates is provided from which the end plate can be selected. Flush end plates are given a 'projection' above and below the connection whilst for extended end plates it is necessary to define the extension (above and/or below).

Chapter 5 : Moment Connections Connections Documentation page 39Bolts and WeldsA wide range of bolt grades and sizes can be defined and, by default, only one pair of 'tension' bolts and one pair of 'shear' bolts are provided. You can add bolts individually or use the Generate Regular Bolt Layout button. In either case you need to go to the Combinations page and click on the appropriate Bolts column to set which of your additional bolts should be used in tension and which in shear. You need to do this for each design combination.

Welds to the beam flanges, beam web and to the haunch if appropriate are all defaulted to 8 mm fillet welds. You should adjust these both in terms of size and type (a butt weld might be more appropriate) to suit the particular application.

StiffenersStiffeners in moment connections are often required and a wide range is provided,

rib usually relatively short stiffeners that are used principally to improve column flange bending capacity,

full depth often required to resist compression particularly where the column is a UB section,

shear these can be diagonal, K or 'Morris' types and may be required to assist the web panel shear capacity,

web plate help both compression and shear capacity of the web panel and have the advantage that they do not interfere with any beams framing into the web,

cap plate can be provided for other purposes e.g. to connect parapet posts but if present will usually assist flange bending, and compression in 'reverse' bending combinations,

flange plate these are 'loose' flange plates i.e. they are not fully welded to the flange - they are usually tack-welded to keep them in place during transport and erection. They assist flange bending,

extension plate for an extended end plate connection the extension can be relatively weak in bending and this vertical stiffener will improve the capacity. It is essential when there are two rows of bolts in the extension.

Note that incorporating stiffeners is expensive in fabrication terms and most can interfere with other members framing into the same area. It is often economic to avoid stiffeners by increasing the section size (of the column and possibly the beam) or deepening the haunch. This may also avoid detailing issues and improve erection efficiency.

Connections Documentation page 40 Chapter 5 : Moment ConnectionsDesign ForcesThe design forces for moment connections are shear in the plane of the web of the beam, moment in the same plane and where appropriate axial force in the beam. Tie forces are not included. For haunched connections, the moment at the 'sharp end' of the haunch can be entered - due to the length of a typical haunch this can be significantly less than that at the connection interface. This moment is used to check the capacity of the beam web at that position. A set of these design forces can exist for each design combination and these are established from the analysis of the building model as a whole (or entered independently in the stand alone application). You can edit the design forces, delete and add load combinations and these changes will be reflected in the design of the connection immediately following the changes. However, all these changes will be lost if subsequently you use the 'Update Connections' function in Building Designer.

Limitations and Assumptions

LimitationsThe following limitations apply:

fully welded moment connections are excluded, section types other than I- and H-sections cannot be used in moment connections, moment connections into the column web are not be permitted, the section size either side of a beam to beam moment connection must be the same, where beam to beam moment connections are formed between beams at different angles,

the connection is assumed to be symmetrical - see figure, the projecting portion of an extended endplate both above and below is limited to have no

more than two rows of bolts, where the projecting portion of an extended endplate either above or below has two rows

of bolts, an extension stiffener must be provided, all components have only one value of design strength, py, taken as the lower of the two

values based on flange thickness and web thickness. However, a built-up haunch will have a value of py for the haunch web and another for the haunch flange.

when checking stiffeners in conjunction with, say, a web, the lower of the two values of py is used. This particularly affects S275 stiffeners used in conjunction with S355 sections.

where more than one beam connects to the face of the supporting member, Building Designer cannot form the connection.

Where a component is excluded e.g. channel section beams, Building Designer will not create a connection to that beam. In addition, where a connection would otherwise be created on one face of the supporting member but on another side a connection cannot be created then no

Chapter 5 : Moment Connections Connections Documentation page 41connection at all will be created. For example, no connection will be created in the case where a plated section beam connects to one flange of the column and an I-section connects to another face.

AssumptionsEssentially the assumptions in Fastrak Connections are those inherent in the design model for moment connections given in SCI P207.(Ref. 2) However, a number of specific assumptions are made as given below. It should be noted that, in principle, the design model in SCI P207 is for moment connections with axial load and not axially loaded connections with moment.

Internal forces in a column from the applied loading that it carries are assumed not to influence the connection design. For example, the axial force in a column from floors above is assumed not to affect significantly the performance or behaviour of the connection.

Similarly, where moment connections and simple connections are connected to the same column it is assumed that the forces imparted by the one do not influence the other. A typical example might be moment connections to the column flanges with simple connections to the column web. Not only are the designs independent but also the detailing. Hence, in this example any stiffening required by the moment connections is assumed not to interfere with the simple connections framing into the web.

Any moment or shear force out-of-plane of the beam web (minor axis moment and shear force) is assumed not to influence the connection design. In the Design Options off the Design menu in Building Designer, you can specify limits for these forces below which you believe the design will be unaffected. If Building Designer detects forces greater than these limits, the design will still proceed but the connection will be given a Warning status and the value of these forces will be given in the results. The default values for these limits are,

minor axis shear - 0.5 kN minor axis moment - 0.1 kNm

Where the members of a moment connection are skewed or rotated relative to each other, Building Designer takes the following approach (see also Global analysis),

where both the skew and rotation angles are less than a given lower limit, then the angles are ignored and the design proceeds as if the angles were zero,

Connections Documentation page 42 Chapter 5 : Moment Connections where either angle is greater than a given upper limit, then Building Designer creates the connection but the design is not performed and the connection is given a Beyond Scope status,

where one angle lies between the upper and lower limit, then the angle is ignored, the design proceeds as if the angle is zero and the connection is given a Warning status,

where both angles lie between the upper and lower limit, then Building Designer creates the connection but the design is not performed and the connection is given a Beyond Scope status.

In cases where the angle is above the lower limit, the angle can be viewed in the design results (on the Notes page). The upper and lower limits are,

lower limit for skew and rotation - 0.5 deg upper limit for skew - 5 deg, and for rotation - 2.5 deg

For double sided beam to column moment connections and for beam to beam moment connections in Building Designer, the top flanges of the beams are assumed to align. However, within the building model beams can be given an alignment relative to its 'cardinal points' - the default is at the centre of the top flange. Any changes that you make to the cardinal points are not reflected in the moment connection design. For example in a double sided beam to column moment connection if you set the cardinal point of one beam to the centre of the top flange and the cardinal point of the other beam as the centre of the bottom flange, the moment connection design will assume, still, that the top flanges align. The design will consider that the connection is double sided even though in this case the two connections should be treated as single sided.

A similar situation occurs when the beams have the same cardinal point but the beams are defined on two separate grid lines that are close together. In this case Building Designer will create two separate single sided connections even though the grid lines may be only a few millimetres apart! Note that for this reason in the stand alone application if you specify 'levels' for the two beams that would effectively mean that they should be treated as two separate single sided connections, Fastrak Connections will still consider them as double sided.

In beam to column moment connections the centre lines of the beams and the column are assumed to 'node'. However, within the building model both the column and the beams can be set 'off-grid'. Any changes you make that set beams or columns off-grid will not be reflected in the moment connection design. It is likely that when transferring significant moment, anything but the very smallest of offsets would invalidate the design model.

Design ChecksThe design checks for bolted moment connections are given in SCI P207. The design models in P207 cover I- or H-section beams to the flange of I- or H-section columns with or without haunches. They can be single or double-sided. For such connections the design models are clearly laid out in P207 and so no general explanation is given here. You are reminded that, in principle, the design model in P207 is for moment connections with axial load and not axially loaded connections with moment.

However, Fastrak covers a somewhat broader spectrum and so additional points of note are given below.

Chapter 5 : Moment Connections Connections Documentation page 43SCI P207 was written in 1995 and so reflected the then current British Standard, BS 5950-1: 1990. However, Fastrak uses the latest British Standard, BS 5950-1: 2000 which incorporated a number of changes that affected connection design. These are, in brief,

modification to the buckling check for unstiffened column webs in compression, modification to the configuration of the stiffened column web and to the design force that

it must resist, changes to the requirements for weld design - both calculation of resistance and the force

for which it should be designed.

The standard formulae for bearing and buckling of the unstiffened column web assume that the column flange at the point of compression is effectively held against both,

rotation relative to the web, lateral movement relative to the other flange.

Where this is the case the effective length of the unstiffened or stiffened web is taken as 0.7L. However, this may not always be the case. Fastrak always assumes lateral restraint to the flange but you are provided with a means to select whether rotational restraint is present or not. In the latter case, you can adjust the effective lengths for the top and bottom of the connection (since they may be different) - the default value is 1.0 L. A similar provision is made for the stiffened capacity.

The centre of rotation of the connection is assumed always to be the intersection of the centre-line of the compression flange with the outside face of the column flange. This position is assumed irrespective of whether some of the beam/haunch web is taken into account in resisting the compression force at that level. Similarly for a stiffened extended end plate the centre of rotation of the connection is not allowed to be within the stiff extension - no guidance exists on how far within the extension the centre of rotation can be placed and so in the meantime the conservative approach is adopted. Whilst the centre of rotation is kept constant, the centre of compression is allowed to move. This is the case when you request that the beam flange bearing check takes account of some of the beam web in its resistance calculation. In this case, the lever arm for each individual bolt is adjusted to take account of the movement of the centre of compression.

When a connection contains a haunch, there is a compressive force at the level of the haunch flange/end plate intersection which can be derived from the equilibrium condition of the potential resistances of the components of the connection at that interface. In the conventional approach contained in SCI P207, all this force is assumed to 'pop out' of the flange at the sharp end of the haunch. A more accurate, more logical and less conservative approach is to use the equilibrium condition at the sharp end of the haunch under the moment at that point. Using this approach the forces at the sharp end can be resolved to give a force acting perpendicular to the web of the beam. The unstiffened or stiffened resistance of the beam web is checked against this force. You can see from the Combinations page of the connection input dialogue that the moment used to determine the equilibrium condition at this point is termed, "Moment (Sharp End)".

Note that whilst within Fastrak Building Designer, the moment, shear and axial force at the connection interface are automatically entered into the design combinations, the moment at the sharp end is not. You will have to interrogate the bending moment diagram for the individual beam members to establish the value of the moment at the sharp end and enter this

Connections Documentation page 44 Chapter 5 : Moment Connectionsdirectly. Also note that the effective length of the unstiffened or stiffened beam web is dependent upon the restraint conditions of the flange in a similar manner to that described above for the column web.

There are a number of points associated with stiffener design, as follows, In positive bending, for a full depth stiffener to be effective in compression, it must be

placed with its centre-line within the stiff bearing length of the haunch flange or beam bottom flange. In negative bending, for a full depth stiffener or cap plate to be effective in compression, it must be placed with its centre-line within the stiff bearing length of the beam top flange.

It is assumed that for a tension stiffener to be effective in generating the yield lines around the bolts, the gross depth of the stiffener should be at least 75 % of the outstand of the column flange or end plate. Where this is not the case a warning is issued.

Stiffeners may optionally be defined 'fitted to root'. This means that the corner of the stiffener is shaped to fit tightly into the root radius of the section. This facilitates the weld runs being taken around the corner of the stiffener. In the normal situation the corner of the stiffener is chamfered so that it clears the root and in this case the weld run must stop at this position. The implication for design is that in the normal situation the length of weld used to calculate its resistance is based on the dimension of the stiffener less two leg lengths of weld (see Clause 6.8.2 of BS 5950 1: 2000). However, where the stiffener is 'fitted to root' only one leg length need be deducted.

A number of options exist for the detailing of cap plates. Normally a cap plate will sit on top of the column and be welded one side (inside) or both sides. The choice between these two weld details is given to you. The full depth stiffener at the base of a connection is usually assumed to be 'fitted'. Suitable details for the cap plate can be made such that a cap plate also can be assumed to be fitted. Hence, you are provided with the choice of assuming that a cap plate is fitted or unfitted. In the former case, in compression, the weld size will be determined whereas in the latter case only nominal welds are required. In both cases in reverse bending the weld is checked for any net tension force.

The weld between the haunch flange and the beam flange is required to resist the force derived from the equilibrium condition at the 'sharp end' of the haunch (in the same manner as described earlier for the beam web in compression). Advantage is taken of the increased depth of the section at this point due to the presence of the two flanges (haunch and beam) in determining the force available to enter the haunch flange. This is resolved into the direction of the haunch flange to provide the design force for the weld. Similarly, the force that continu

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BS5950 - Connections Handbook