You can convert most linear IFC reference objects such as beams, columns, braces, plates, slabs, footings and walls into native Tekla Structures objects. Conversion also supports polybeams that have curved sections, and have originally been exported from Tekla Structures, and double type UDAs. The purpose of converting IFC objects in Tekla Structures is to help in the creation of the structural model and to avoid rework in an early modeling phase. In IFC object conversion, IFC objects are converted either as items or as
extrusions. Conversion as item means that an IFC object is converted as a Tekla Structures item, where the 3D shape defines the geometry of the item.
Conversion as extrusion means that an IFC object is converted as a part (column, beam, plate, etc.) that has a profile extruded to create the length of the part.
In IFC object conversion you need to do the following:
1. Before converting, check that the profiles and units in the IFC reference model are compatible with your environment.
2. Check the object conversion settings in the IFC object conversion
settings dialog box and change them, if needed.
IFC 58 Convert IFC objects into native Tekla Structures objects
3. Convert the IFC objects to native Tekla Structures objects. There are two alternative ways available in object conversion:
• Converting all selected reference model objects at one go using the
Convert IFC objects button on the Manage tab.
• Converting using the IFC object conversion change management. You can also perform an update conversion with a new reference model revision using the change management.
Is object conversion always necessary?
In Tekla Structures, reference model objects can be used in a way similar to the native objects, for example, in clash detection, reporting and scheduling. There is no need to have everything as native, because the reference model objects can also be used in many ways. For example, reference model objects can be shown in drawings and they can be listed in reports.
The reference files have the benefit compared to the copied files that the content of the files is automatically updated by the designer of that design discipline.
Profile conversion logic in IFC object conversion
Tekla Structures uses a certain logic in converting profiles in IFC object conversion.
Parametric profile used in IFC model, I-, L-, U-, C-, T-, Z-, Rectangle- and Circular type profiles can be defined parametrically:
1. If IFC file has been created with Tekla Structures, original profile name is used.
2. If profile with same name is found from Tekla Structures Profile Catalog, it will be used.
3. Otherwise, Tekla Structures checks parameter values to find a corresponding profile. If found, that will be used.
4. Otherwise, a default parametric profile is used.
Arbitrary profile used in IFC model, profile shape is defined with polygon: 1. If IFC file has been created with Tekla Structures, original profile name is
used.
2. If the shape is detected and found from Tekla Structures catalog, that profile will be used. The shape detection supports the standard types of hot rolled profiles.
3. Otherwise, a new profile is created based on the description of the arbitrary profile.
B-rep geometry used in IFC model, object is defined with surfaces and profile geometry information is not available:
IFC 59 Convert IFC objects into native Tekla Structures objects
1. If corresponding item exists in Tekla Structures model, it is used. 2. Otherwise, a new item will be created and used.
If Conversion as item is used for extrusion type of part, new item is always created.
Example: Convert IFC objects into Tekla Structures objects
in one go
In this example, you use an IFC model as a basis for your structural model. You will convert the beams and columns into native Tekla Structures objects.
1. Hide irrelevant IFC layers:
a. Click the Reference Models button .
b. In the Reference Models list, double-click the reference model to open the details.
c. Open the Layers list by clicking the down arrow on the right. d. Hide the unnecessary layers by clicking the eye button next to the
layer.
IFC 60 Convert IFC objects into native Tekla Structures objects
2. Select all visible IFC objects.
3. On the Manage tab, click Convert IFC objects. Tekla Structures converts the reference objects.
4. Check the profiles and materials of the IFC objects and map missing material:
a. On the File menu, click Settings --> IFC object conversion settings. b. Click Check.
Tekla Structures lists the missing profiles and materials. c. View the Missing Profiles and Missing Materials tabs.
Tekla Structures lists a missing reference part material Concrete
Block.
d. Select CONCRETE_UNDEFINED from the list.
IFC 61 Convert IFC objects into native Tekla Structures objects
e. Click Update Mapping Catalogs and Close.
f. Select the Create report after conversion check box. g. Click OK in the IFC object conversion dialog box. 5. On the Manage tab, click Convert IFC objects again.
Tekla Structures converts the objects.
The Class for all the converted objects is 992. That means that the profile of the converted object may be incorrectly rotated because there is no parametrized profile data in the IFC model.
6. Check the conversion changes list:
• Select objects in the changes list to highlight them in the model: Use the buttons Select objects in model view and Zoom to selected. • Compare the converted objects with the IFC objects.
• Use the Inquire objects button on the ribbon to view detailed information on objects.
IFC 62 Convert IFC objects into native Tekla Structures objects
Below is an image of converted beams and columns.
Limitations in IFC object conversion
Tekla Structures is dependent on the quality of the IFC model, because it uses information available in the model when converting objects.
Tekla Structures converts most linear IFC objects to native Tekla Structures objects.
The following limitations exist in IFC object conversion:
• If the IFC model does not comply with standard, it might not be converted as expected.
• Bolts, reinforcement and welds cannot be converted to native Tekla Structures objects.
• The currently supported physical elements: IfcBeam, ifcColumn,
ifcMember, ifcPile, ifcFooting, ifcPlate, ifcDiscreteAccessory, ifcSlab, ifcWall, ifcWallStandardCase, ifcRailing and ifcBuildingElementPart.
• Only SweptSolid, Brep, CSG and Clipping representations are supported. • Multiple representations for one object are not supported.
• Profile offset is not supported.
• Profiles with more than 99 polygon points are not converted correctly.
IFC 63 Convert IFC objects into native Tekla Structures objects
• Sometimes, chamfers may be converted incorrectly.