Design Requirements for a Model - Robot Structural Analysis Method

Ensure the model fulfils design requirements before you start the design.

Note: The Robot Structural Analysis method is recommended for advanced users of Robot.

Rozszerzenie Projekt belki kompozytowej requires that beams and slabs from the Robot model to be designed must fulfill the following requirements.

Beams

• Must be linear.
• Must be AISC Standard Wide Flange shapes.

  In Robot, select the AISC section database.

  In Robot, select Tools > Job Preferences > Databases > Steel and timber sections. 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

• Exactly one slab reinforcing all members in one selection group.
• Entire design area must be within slab (no edges inside design area).
• Slab must be planar (no warped slabs).

Geometry settings

• Releases on beam ends must be set to Pinned-Pinned.

  In Robot, Fixed-Fixed is a default setting for beam end releases. Change this setting to Pinned-Pinned:

  1. Select beams and click Geometry > Releases.
  2. In the Releases dialog, select Pinned-Pinned and click Apply.
  3. Accept changes in the model.

     After the model is changed, perform static calculations to obtain up-to-date results.

• Parameters of the panel calculation model for a slab must be set to No finite elements.

  In Robot, to modify this setting:

  1. Select the slab.
  2. Click Geometry > Properties > Panel Calculation Model.
  3. In the Panel Calculation Model dialog, double-click Deck slab (one-way).
  4. In the dialog with parameters of a panel calculation model, for Elastic stiffness select No finite elements. Click Add and Close.
     Note: You cannot modify the default set of parameters. Change the default Deck slab (one-way) label to save changes.
     
  5. In the Panel Calculation Model dialog, verify if the Panel field displays the panels to which the calculation model should be assigned.
  6. Click Apply and accept changes in the model.
Note: After the model is changed, perform static calculations to obtain up-to-date results.

If the model does not fulfill these geometry requirements, in Rozszerzenie Projekt belki kompozytowej during verification, beams are treated as non-composite. In most beams negative moments occur then, causing tension in the RC slab.

Warnings about Node Releases

During design calculations based on the Robot Structural Analysis method, you may receive a number of warning prompts resulting from too many releases at some nodes. This type of warnings is for information, and does not involve any risk to the model because Robot applies automatic constraints during calculations.