| Applies To | |||
| Product(s): | STAAD.Pro | ||
| Version(s): | All | ||
| Environment: | N/A | ||
| Area: | Design | ||
| Subarea: | American Steel Design | ||
| Original Author: | Bentley Technical Support Group | ||
When I run code checking [as per BS5950] of the steel prismatic members which were defined in the User Provided Table, I get the following message in my output file:
CHECK CODE ALL
DESIGN NOT PERFORMED WITH PRISMATIC PROPERTIES
USER-TABLE MAY BE USED TO DESIGN PRISMATIC SECTIONS
The program is not designing the steel members defined as "Prismatic" in the UP Table, whereas all other members defined otherwise as Tee, Channel etc are being designed. Also I couldn't understand the meaning of the last line "User-Table may be used to design prismatic sections".
Since PRISMATIC sections by definition are those whose section shape is not one of the standard shapes like a W, C, Angle, etc., there are no readily available rules in the code to follow. Due to this reason, prismatic shapes are presently not designed per the BS code nor the AISC code.
You may get around this problem by defining the properties using the GENERAL section in a User Provided Table. For a GENERAL section, STAAD provides the means for providing dimensions of the components that are critical from the standpoint of computing allowable stresses, such as flange, web, etc. The allowable stresses for a GENERAL section are computed using the rules of a wide flange shape (I shape). As a result, the allowable stress value will be dependent on attributes such as dimensions of the cross section, length of the member, etc.