Use the default, simplified method of calculating internal forces recommended for all users.
When you use this method, the extension:
- Estimates an influence surface on a slab
- Assigns loads from this surface to the beam supporting the slab.
Beams
- Must be linear.
- Must be AISC Standard Wide Flange shapes.
In Robot, select the AISC section database:
- Select Tools
Job Preferences Databases Steel and timber sections.
- From the database list, select AISC 14.0 (American hot rolled shapes), and click OK.
- Select Tools
- Must be in plane.
- Cannot cross other beams.
- Cannot form a circular bearing chain with other members.
- Slab and all beams must be associated with the same level.
Slabs
- Slabs must be one-directional.
- A selection group includes exactly one slab reinforcing all members.
- Entire design area must be within slab (no edges inside design area).
- Slab must be planar (no warped slabs).
Loads
- All point and line loads must be applied to a member in the design area.
- Point loads are not counted if they are applied to the end of a member, they are assumed to be supported by whatever is supporting the member.
- Point loads at the intersection of more than one member are applied to the first qualifying member only.
- Only the component of a load normal to the plane of the design area will be included in the design.
- Area Loads can be applied to any slab area and can vary in up to one direction. The extension does not support loads tapered in more than one direction.
- Load from columns are not taken into account. Concentrated loads must be defined by the user.