IFC Steel Model
IFC (Industry Foundation Classes, .ifc) is the open model format of building and structural engineering: BIM
programs (Tekla Structures, Revit, Allplan, Archicad), viewers (BIMcollab Zoom, Solibri, the free web viewers) and
steel fabrication and erection management programs read it. ParametrIQ CAD writes a structural steel drawing's pieces
as an IFC4 model (ISO 16739-1:2018, IFC4 ADD2 TC1), as an ISO 10303-21 STEP file, for the Design Transfer View:
real solids with their sizes, holes and copes, so the model can be checked against the rest of the structure, its
pieces counted and weighed, and its marks and grades looked up.
To write one, use File › Export › Export… and choose IFC Files (Steel Model). A drawing whose industry is Structural steel offers it among its first formats.
What is written
The pieces are the ones the DSTV NC export finds: each closed outline on the Cut layer, with
what is cut inside it, named by its Part Mark (else numbered), its profile, grade and
quantity from the drawing's classification (profile, grade, quantity, thickness).
| In the drawing | In the model |
|---|---|
| A plate (no profile, or a PL/FL profile) | An IfcPlate: its outline extruded through its thickness, lying flat; slots and other cut-outs as voids in its profile |
A piece of a profile (CLASSIFY "profile","IPE 300") |
An IfcBeam: its section (IfcIShapeProfileDef for I and H sections, and the channel, angle, tee, hollow section and round bar sections when their sizes are known) extruded along its length, its web upright as the drawing shows it |
| A round hole (Cut or Drill layer) | An IfcOpeningElement voiding the plate (IfcRelVoidsElement) |
| A beam's copes (where its outline leaves its full length × depth) | One IfcOpeningElement cutting them through the section's width |
| The piece mark | The element's name and Tag, and Reference in Pset_PlateCommon / Pset_BeamCommon |
| The grade | Its IfcMaterial (category steel) |
| Length, width, area, weight | Qto_PlateBaseQuantities / Qto_BeamBaseQuantities (Length, Width, NetArea, NetWeight), as the Steel cutting list works them out |
| Quantity, profile, grade, order, drawing, phase | Property set PiQ_Fabrication |
The pieces stand side by side along the model's y axis, a gap apart, in a project, site, building and storey named after the file. Lengths are in millimetres. The ids (GlobalId) are made from the project's name and each piece's mark, so exporting the same drawing again gives its pieces the same ids, and a BIM program can update them.
Options
| Option | What it does |
|---|---|
| Project name | The IFC project's name (the file's name to start with). |
| Holes and copes as openings | Round holes and copes as opening elements, as fabrication models carry them. Off: round holes are left in the plate's outline as voids, and copes are left off. |
| Gap between pieces | How far apart the pieces stand. |
| Every page | The pieces on every page (3D pages left out); else only the page worked on. |
Notes
- A profile's section comes from the sizes the DSTV export knows: EN 10365's IPE, HEA and HEB, or the sizes typed in its options. Other profiles without sizes are written as a rectangle of the piece's height and the flange width (or web thickness): give their sizes in the DSTV options, or check them in the BIM program.
- Arcs in outlines are written as short straight lines within 0.1 mm.
- A single drawing's pieces are written as made, side by side. A structure - a drawing that places other drawings as members, or a steel drawing whose pieces are put together by mates - is written as it stands instead: each piece where it is (a triangulated face set), each bolt an IfcMechanicalFastener connecting the pieces it goes through, each weld an IfcFastener (WELD). See Steel structures.
See also: DSTV NC, Structural steel, Formats.