Simple Connections
Simple connections are by definition pinned connections and transfer vertical shear only. Fastrak 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 e.g. if the supporting beam is not an I-section or the supported beam frames in at a steep angle.
Simple 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 in 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,
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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.1When a particular type of connection is established by Fastrak in the building model e.g. fin plate for beam to beam connections, the default settings for bolt size and number, fin plate thickness etc. are such that the subsequent check of this connection should under normal circumstances give a Pass. This is because simple connections are more about detailing than design i.e. a well detailed simple connection will usually be adequate in design. This has been underpinned in Fastrak by careful selection of the defaults to ensure that the 'Recommended Details' and standard connections contained in the 'Green Book' on simple connections are followed.
This all means that as a designer, once you have selected the type of connecting element for a particular situation e.g. fin plate for beam to beam connections, Fastrak 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 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 Connections
Moment 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 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
Footnotes
Advisory Note for Fastrak Building Designer page 98 Integrated connection design : Chapter 21 : Practical Applications
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 Fastrak 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 one 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,
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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.
You may prefer to adjust the moment connections 'inside' Fastrak 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 Fastrak 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.
Fastrak 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.
Column Base Connections
Integrated connection design : Chapter 22 : Scope Advisory Note for Fastrak Building Designer page 99