The latest version of our StruSoft StruXML Add-In contains a new workflow possibility, which is import a FEM-Design model into Revit. The new transfer direction is a great opportunity for those who usually start their job in FEM-Design and want to be able to reuse that model in Revit.In this article I would like to highlight some of the issues that one may encounter while integrating a FEM-Design model into Revit.
1. Compatibility with older FEM-Design models
It is not recommended to import FEM-Design
models created in version earlier than 13 into Revit. It cannot be guarantee
that all files created in older version will be properly recognized in Revit
and in many cases an Invalid file warning
may appear when trying to import such file.
It is because the "Import StruXml" feature has been implemented for a current version of the struxml schema, which includes significant differences compared to the one corresponding to older versions of FEM-Design.
2. Mapping
The transfer of the model between the
two programs is based on the mapping of every unique material and
element type used in FEM-Design model to a corresponding material and
element type in Revit.
At
the current version of the StruXML Add-In there is no possibility to
add or create a new material or element type from the mapping
dialog, so it is required that all the necessary materials and element
types exist in the Revit project prior to import.
3. Modeling discrepancies
Modeling discrepancies between FEM-Design and Revit are probably the biggest challenge of the link between the two programs. Shortly speaking, there are at least couple of cases where something can be done in FEM-Design, but it cannot be done in Revit. I will explain that using some example.
a. Example 1: Supports
In FEM-Design support conditions can be applied to any element, at any location. They can be even placed independently without any host element.
In Revit however, each of the boundary element (support) needs a host element. Apart of that:
So if a FEM-Design model imported to Revit contains a support condition that is not possible to recreate in Revit, an error message will be thrown in a format: Point support / Line support / Surface support”, “support
name and ID from FEM-Design”, “reference not found”
b. Example 2: Wall foundations
The next situation when an error will be thrown, is an import of a wall foundation without a host wall, or attached to other element than a wall. Situation like this is not possible in Revit where wall foundation can only be attached to a wall element. An error message will be thrown in a format: “Wall foundation”, “wall foundation name and ID from FEM-Design”, “wall not found”
c. Example 3: Floor geometry
In FEM-Design it is possible to create a floor of a geometry shown in figure below. The tricky is that the boundaries of both the openings meet in one point.
So if a FEM-Design model imported to Revit contains an object of a geometry that is not allowed in Revit, an "Unexpected error" will be thrown and the import process will be terminated. In such case, I recommend importing the model in parts to see what the problematic element is. But if you are unable to find the error, you are welcome to write to the FEM-Design support, or directly to me at iwona.budny(at)strusoft.com.
4. Recognized issues:
Very rarely, a wall opening cannot be recreated while importing the wall into Revit and an error message will be thrown in a format: “Wall”, “wall’s name and ID from FEM-Design”, “Revit function failed to create an opening for a certain wall”.
The second issue is most probably due to some Revit bug. Sometimes, you may see a following warning:
Modeling discrepancies between FEM-Design and Revit are probably the biggest challenge of the link between the two programs. Shortly speaking, there are at least couple of cases where something can be done in FEM-Design, but it cannot be done in Revit. I will explain that using some example.
a. Example 1: Supports
In FEM-Design support conditions can be applied to any element, at any location. They can be even placed independently without any host element.
In Revit however, each of the boundary element (support) needs a host element. Apart of that:
- a Point boundary condition can only be applied to an end of a framing element,
- a Line boundary condition can only be applied to a whole length of a framing element or to an edge of a surface element
- an Area boundary condition can only be applied to an structural floor or foundation slab.
b. Example 2: Wall foundations
The next situation when an error will be thrown, is an import of a wall foundation without a host wall, or attached to other element than a wall. Situation like this is not possible in Revit where wall foundation can only be attached to a wall element. An error message will be thrown in a format: “Wall foundation”, “wall foundation name and ID from FEM-Design”, “wall not found”
c. Example 3: Floor geometry
In FEM-Design it is possible to create a floor of a geometry shown in figure below. The tricky is that the boundaries of both the openings meet in one point.
If you try to draw a similar object in Revit, you will quickly find out that it is not possible.
The quick solution to this particular issue is to divide the floor in FEM-Design, just in the place where the common point is. This way we will get two separate floor elements of separate boundaries.
So if a FEM-Design model imported to Revit contains an object of a geometry that is not allowed in Revit, an "Unexpected error" will be thrown and the import process will be terminated. In such case, I recommend importing the model in parts to see what the problematic element is. But if you are unable to find the error, you are welcome to write to the FEM-Design support, or directly to me at iwona.budny(at)strusoft.com.
4. Recognized issues:
Very rarely, a wall opening cannot be recreated while importing the wall into Revit and an error message will be thrown in a format: “Wall”, “wall’s name and ID from FEM-Design”, “Revit function failed to create an opening for a certain wall”.
The second issue is most probably due to some Revit bug. Sometimes, you may see a following warning:
You can just ignore, as it can be shown even if you do not have any rotated column in your model, so consider it only as a bug.
