Only lateral members are included during the meshing process. Gravity members are only considered in finding closed beam loop if Use Beams for Exterior Boundary option is chosen or for inserting vertical springs or vertical gravity members as gravity columns and walls. Refer to Diaphragm Out-of-Plane Stiffness for details.

All openings are accounted for but penetrations are not. After the meshing is completed, the diaphragm is represented with a collection of finite shell elements. For each shell, the program calculates its properties (such as thickness, E, etc… ) based on the information assigned to decks in the Modeler. This process is internally taken care of by the program so that the user does not need to go through this tedious task manually. The Model Data report provides more information regarding calculated shell's properties.

During the meshing process, the following details are taken care of by the program automatically:

• Walls and Semirigid Diaphragms: when a wall is found to be a part of the diaphragm, the mesh around the wall is generated in such a way that both the diaphragm and the wall are attached to the same mesh nodes. This provides compatibility between the diaphragm and the walls (hence, the load transfer from the diaphragm to the wall is ensured in analysis).
• Columns and Semirigid Diaphragms: Similarly, when a column is found to be attached to a semirigid diaphragm, the interaction between them is taken into account in such a way that both the column and the diaphragm are attached to the same column point (hence, both load transfer and compatibility fulfilled).
• Beams and Semirigid Diaphragms: Beams located inside the diaphragm are also meshed along their lengths. Note that the meshed beams are attached to the diaphragm at the nodes created along their lengths. It is always guaranteed that no individual shell element crosses the meshed beams.
• Deck Geometry: Any changes in deck geometry are considered during the meshing process. Thus, no finite element is created that crosses decks with different properties (i.e., E or thickness).
• Sloped Diaphragms: A sloped diaphragm can be defined by setting correct orientation of decks located inside the diaphragm. Each deck represents a unique plane and by adjusting column and wall elevations inside the deck, you can create a sloped plane for the deck. It is assumed that each sloped deck constitute a flat-plane (no warped surface allowed). An example is given in Sloping Framing Effect .
• Column Drop Zones: The program considers column drop areas during meshing process. Generated final mesh visually shows column drop zones.
• In the Story Displacement report, diaphragm mass center location is used to show story displacements for semirigid diaphragms.
• For openings located inside a semirigid diaphragm, the program skips member self weights and mass for columns and walls that are located inside these openings.