0 Votes

Boundary conditions (supports)

Last modified by Iwona Budny Bjergø on 2023/07/03 09:46

In Revit, Boundary Conditions command allows to choose between three kinds of boundary conditions: Point, Line, and Area. User has to assign it with one of predefined or user defined State in X, Y and Z direction: Fixed, Pinned, Roller, and User.  The exact definition of boundary conditions can be exported from Revit to FEM-Design as follows:

Boundary Condition Type:

  • Point: exported to FEM-Design as Point Support Group
  • Line: exported to FEM-Design as Line Support Group
  • Area: exported to FEM-Design as Surface Support Group

State:

  • Fixed: exported to FEM-Design as type Hinged
  • Pinned: exported to FEM-Design as type Rigid
  • Roller: exported to FEM-Design according to Revit definition
  • User: exported to FEM-Design according to Revit definition

/

“Rigid” value

The “Rigid” value exported from Revit to FEM-Design is equal to: 1e+15 kN/m for motion, and 3.046e+11kNm/° for rotation.

Special case

Line boundary conditions under curved walls are special case. Each curved wall exported from Revit, in FEM-Design will be divided into a number of straight walls. But line boundary condition will remain curved, as shown in the left part of the figure below. It is therefore, user’s responsibility to verify the support condition under curved walls in order to obtain a desired solution as shown in the right part in figure below.

1553089212049-941.png