Wednesday, August 04, 2010

Prep a Pro Model for Femap Solid Mesh - Weldment

I need to import a ProE model into Femap, and generate a solid mesh on it. In ProE, weldments are often modeled as separate parts that are placed together in an assembly. In Femap, the solids are auto-meshed separately, so that the intersections or "nodes" on one part don't necessarily match up to those on another. To get around this, I'm making a single ProE part model that is based on the assembly, so that in Femap it is all one piece.

To do this, I'm using some surface modeling techniques. The new one-piece model that is created will be associated to the original assembly, so that changes to the assembly will be reflected in the one-part version of it.

Open the assembly, and pick "create a component in assembly mode". Name it, and choose "Default Constraints" to place it. This model will be the solid version of the weldment, which will be exported to Femap.

Right-click the new model in the hierarchy, and activate it, so the new items we create will go into the new model rather than into the assembly.

Next, copy the surfaces of the assembled parts, and paste them into the new model. This is done one part at a time. See the following for the steps:

Select the surfaces of one part:

Copy the surfaces, and paste them into the new (active) model:

Repeat the process of copying and pasting surfaces until all surfaces have been copied to the new model. Middle-mouse click will also "accept", which may be faster than a screen click.

In wireframe view mode, solid edges are white, while surface edges are purple or magenta. Purple indicates that the surfaces can be turned into solids. Switching in and out of wireframe mode can help you identify whether all of the desired surfaces have been copied to the new model file, and which you are missing.

Open the new model. Select one of the surface copies, and pick Edit/Solidify, then accept (middle-click). Repeat until all of the copies have been solidified.

As the surfaces are solidified, the edges turn white again in wireframe.

Save, and now you have a single solid model for the weldment. Updates to the original assembly will be reflected in this model, as you regenerate it.

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