Beam Section Dynamic Data

On the Beam Section Dynamic Data tab you can define the steel details along with stud and reinforcement information.

The steel section size and grade are selected from the droplists. A minimum (H.min) and maximum (H.max) depth of section can be set so the droplist only includes sections within these parameters. This can be of benefit when there are floor depth restrictions applicable in the design criteria.

The area of transverse shear reinforcement is defined. You can either select a mesh area from the droplist or overtype it with your own area of reinforcement. This could be an area of bars placed over a metre length instead of mesh, eg, T16s at 300mm c/c (670mm2). There are 2 boxes for mesh - usually the top 'Mesh (mm2)' value is the area of global mesh which applies across the full floor and the 'Add. Mesh' which is an area of additional mesh to be located locally for the particular beam you are working on. The position of the mesh can be specified as either above the head of the studs or to be more than 10mm below the head. This can have an effect on the transverse reinforcement requirements.

In the shear connectors area there are 3 options available.

1. Usually the number of studs per trough for a secondary beam is selected from the list. The capacity of the studs arrangement is then calculated as per the selected design code. For a primary beam the spacing of the studs can be set and whether these are single studs or a pair of studs. The 'As Welded Height' of the stud can be entered in mm. The British Standard asks for the stud height to be at least 35mm above the top of the troughs in the decking, whereas the EuroCode asks for this dimension to be 2 x dia of the stud, eg, 38mm for a 19mm stud.

2. There is also an option for a raised rib pattern on the top flange surface which is usually found on Asymmetrical Slimfloor Beams (ASBs) in a slimfloor construction situation. In this case the raised rib pattern is transferring some of the load from the beam to the concrete in place of studs.

3. The design can also be set so that the beam is considered as Non-Composite (NC). It is often the case that a short span edge beam is more efficient as a steel beam than a composite beam as not enough studs can be welded in place to transfer a share of the load from the beam into the concrete.

When sizing a beam you can manually move up or down the beam section sizes in the droplist until one passes or alter the studs and reinforcement area as necessary. Alternatively, the beams can be sized automatically. The Automatic Design Defaults can be used to size the beams, studs spacing and reinforcement area required. A list of mesh sizes is already entered and can be added to or partially deleted to suit your design requirements. Stud spacings can be specified as well and the concrete grade for the slabs selected. To use the auto design click on the 'auto design'  option. The program will attempt to size the beam, studs and mesh for the moments and forces in the beam. Note that it doesn't take account of any openings when carrying out an automatic design.

When all the beams in a file have been designed, a 'scan for failures'  can be carried out. This will check all the briefs and highlight any that are failing. This is especially useful if a global parameter has been changed, eg, the concrete grade, to ensure all the beams still pass. Any failing briefs will be highlighted and you can move from failing brief to failing brief using the 'find next failure'  option.