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The user has a degree of control over some of the design assumptions that are applied within the program during the design of the composite beam.
There are 3 sections to these design assumptions - General, Shear Connection and Web Openings.
If the beams are set as propped on the Floor Information tab, they are not usually checked for bending at construction stage since the loads are going into the props. However, the user has the option to have the construction stage checked anyway.
Should the user wish to alter some of the program default values, the Use Modified Program Defaults should be ticked. This will open up an additional tab called 'Defaults' on which values can be modified - see next section on Defaults for further details.
The load combinations can be shown in the calculations, especially useful if the calcs are to be passed on to another engineer for inspection.
The steel and concrete stress details can also be shown in the calculations.
The Ignore Deck Contribution in Primary Beams is provided because BS 5950 is unclear about the contribution.
MasterBeam will ignore the contribution if the profile is discontinuous, otherwise the contribution will be assumed to be the same as for a discontinuous profile with ribs running perpendicular to the span of the beam.
There is also an option to use Amendment 1 to BS 5950-3.1. This amendment was brought out in 2010 and should be applied to all new BS design composite beams. Models which were developed and designed prior to this amendment may need the option switched off so the results remain the same as they when they were originally designed.
When the number of shear studs are specified it is often possible to add an additional stud at the start or end of a run. Hence there is an option for increasing the number of shear connectors by 1. For example, if the studs in a 7.1m long primary beam are spaced at a given spacing, say 200mm centres, you could have 35 or 36 studs depending exactly where the first stud is placed. This option gives the user control over the number used in the design.
When holes are provided in the sheeting for the placement of the studs, the contribution of the sheeting to the transverse reinforcement is negated and so more reinforcement area may be required.
The degree of shear connection in composite design has seen much work carried out, particularly by the SCI, to improve the design methods used in both BS and EC design. Options are provided to include this work in the design of the shear connection. These are SCI AD 148 for minimum shear connection in BS design and SCI P405 Minimum Degree of Shear Connection to EC4, NCCI PN001a-GB Resistance of Headed stud shear connectors in transverse sheeting and NCCI PN002a-GB Modified Limitation on Partial Shear Connection.
Web openings can be checked to one of the SCI guides, P355, P068 or P068 with new revisions. P068 is a much older document relating particularly to early BS designs of beams with openings, whereas P355 is much more up to date and contains newer research. P355 is more applicable to EC design of composite beams with openings and supersedes P068.
The option to show the error report is usually ticked by default, although you have the option not to show it if you can justify it.
Similarly, there is an option to ignore the dimensional checks. Again, it is up to the user to justify why these may be ignored.
Add stiffener in calculating Fyt and Fyb - the lower and upper web/flange capacities below and above an opening are calculated based on the available area. If stiffeners have been applied around the opening these can also be considered to contribute to the axial capacities.