Stud Criteria dialog
This dialog is used to display and change the current stud criteria for composite beam design.
For a complete explanation of stud distribution and its effect on design, see the Technical Notes chapter of the RAM Steel Beam manual.
Dialog Controls
Stud criteria may be changed for the current beam data by typing the desired values in the appropriate edit boxes, and then clicking OK. Clicking Cancel will cancel any new selections made.
| Setting | Description |
|---|---|
| Maximum % of Full Composite Allowed | Specify an upper limit on the percentage of full composite action to be used. The codes allow composite beams to be fully composite (100%). This option allows the engineer to limit the percent composite to be something less than full composite. The impact of this may be that a larger beam size with fewer studs is selected rather than a smaller beam with more studs. |
| Minimum % of Full Composite Allowed - Short Spans / Long Spans | Specify a lower limit on the percentage of full composite action to be used.
The various codes differ on the minimum percent allowed, and these lower
limits are enforced by the program, but this option can be used to specify
some greater minimum (the program will enforce the larger of the
code-specified minimum and the user-specified minimum). Separate values can
be specified for long-span beams and short-span beams if desired, with the
ability to specify what span length defines those. The impact of specifying
a minimum percent may be that more studs will be assigned to the beam, or in
some cases a larger beam size if the additional studs won't fit on the
smaller beam. Use the Long Span Defined as Spang Greater than field to define the length of a "long span." |
| Maximum Rows of Studs Allowed | Specify the maximum number of parallel rows of studs along the length of the beam top flange. Code-specified limits will automatically be enforced, this option allows the engineer to further limit the number of rows. |
| Minimum Flange Width for 2 / 3 Rows of Studs | Specify the minimum flange width specified for either two or three parallel rows of studs, respectively . Code-required stud spacing and edge distance requirements should be considered when determining these values. Staggering the studs within a rib may allow use of smaller values of Minimum Flange Width than are provided by default by the program. |
| Maximum Stud Spacing | Options for specifying Maximum Stud Spacing for both conditions of Deck Parallel and of Deck not Parallel to the beam. Per Code will enforce the Code-specified maximum spacing. Limit To will apply the more stringent of the Code-specified maximum and the user-specified maximum spacing. When the deck is not parallel there is an option to specify that the maximum spacing is equal to the Rib spacing, which will result in at least one stud in every rib. . |
| Stud Placement | (AISC 360 only) Select the range in which emid-ht falls. Used in the calculation of Rp. This value is described in AISC 360-10 Section I8.2a. In this section emid-ht is defined as "distance from the edge of the stud shank to the steel deck web, measured at mid-height of the deck rib, and in the load bearing direction of the stud (in other words, in the direction of maximum moment for a simply supported beam)." |
| Stud Distribution | Select if the distribution of studs along the length of the beam top flange is a Uniform Distribution or should be an Optimized Distribution to reduce the number of studs. |
| Stud Placement in Re-entrant Decks | (BS 5950:2000 with Amendment 1:2010 only) Used in calculating the connector capacity as well as the minimum percent composite. Select either Unfavourable or Centre or Favourable. |
| kt, max | (Eurocode only) Options defining conditions for use in the calculation of kt,max, which impacts the shear connector capacity. See Table 6.2 of EN 1994-1-1:2004. |
| SCI P405 | (Eurocode only) Check this option to apply the stud capacity rules given in the SCI Publication P405 Publication titled Minimum Degree of Shear Connection Rules for UK Construction to Eurocode 4. This option provides an alternative method for calculating minimum partial limits, and impacts the minimum composite value and potentially the stud capacity (if there are two rows of studs) and the deflection calculation. The option will override the corresponding (and generally more restrictive) requirements found in the Eurocode. |
| Stud Distribution | For beams with point loads the program will specify studs for each segment between beam ends and point loads, otherwise it will specify a uniform distribution of studs. The engineer can force the program to use a uniform distribution of studs on all beams. The result is a simpler designation of studs but may result in more studs. |
| When beam fails minimum composite requirements | Select to either Use Bare Beam section properties or Use Composite section properties for the condition in which the beam fails minimum composite requirements. |
| Ductility of Shear Connection | (AISC codes only) Check the option to Enforce AISC 360-16 Commentary I3.2d(1) for Spans greater than 30 ft to satisfy the AISC 360 stud ductility requirements for beams with spans greater than 30 ft. This should be selected unless stud ductility will be checked outside of the program. |