IFC Data Exchange

From CAD model to FE mesh
From CAD model to FE mesh

The data exchange format IFC (Industry Foundation Classes) is a manufacturer-independent transnational interface, which supports the exchange of all geometric and alphanumeric BIM data.

buildingSMART International develops and establishes IFC as an open standard for the building information modeling (BIM). IFC is registered as an international standard in ISO 16739.

InfoCAD supports the im- and export of analysis models (StructuralAnalysisView) and building element models (CoordinationView).

The IFC file can contain both models in parallel, so the user has to select the function area for the import:

  • Import of Analysis Model (StructuralAnalysisView)
    Structural data for analytical calculations e.g. supports, beams, surfaces, loads, etc.
  • Import of the Building Element Model (CoordinationView)
    CAD data with component geometries, e.g. walls, slabs, etc.. For an analytical calculation, a analysis model must be derived from this.

Import of an Analysis Model (StructuralAnalysisView)

Selection of the import data
Selection of the import data
Imported analysis model with structural information
Imported analysis model with structural information
The figures above shows the import of an analysis model. The area and beam properties (e.g., cross-section, material, etc.) are transferred. Existing loads are also imported.

Importing of Building Elements (CoordinationView)

Imported building elements with BIM properties
Imported building elements with BIM properties

The figure above shows the import of building elements (CoordinationView) from an IFC file.
In InfoCAD special drawing objects are generated from these that make it possible to continue to use the geometry of the building elements. The snap modes allow you to use, for instance, characteristic points for measurements or for the design of model objects.

Imported building element whose geometric display is based on the extrusion of a base area (IfcExtrudedAreaSolid) and who originate from

  • IfcBeam
  • IfcColumn
  • IfcMember
  • IfcSlab
  • IfcWall(StandardCase)

can be transformed, with the help of the program, into analysis model objects automatically.

Building elements and transformed analysis model
Building elements and transformed analysis model

Because the model objects are created based on the wall or plate axis surfaces, gaps usually exists between neighboring objects (see detail).

As a remedy, all objects are joined with one another during the transformation and, if necessary, marginally reduced or enlarged. If for walls standing on top of each other the wall axes do not match up, for instance due to differing wall thickness, it might be necessary to add transition surfaces that are not perpendicular. In addition, openings that are close to the edge are adjusted.

The described operations help to improve the continuity between the model objects. This can eliminate the need for manual corrections in many cases. The following illustrations show the joined model objects and the element mesh that has been created as a result.

Analysis model and the FEM mesh
Analysis model and the FEM mesh

Export

The analysis model (StructuralAnalysisView, only for static applications usable) as well as the building elements model (CoordinationView, only for frameworks) are exported.
Framework exported with InfoCAD displayed in © Autodesk, Revit Structure
Framework exported with InfoCAD displayed in © Autodesk, Revit Structure