Design Requirements for a Model - Internal Engine Method

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:

  1. Select Tools Job Preferences Databases Steel and timber sections.
  2. From the database list, select AISC 14.0 (American hot rolled shapes), and click OK.
• 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.