Getting Started with Femap

Geometry Preparation and Clean-Up


In this step we’ll start on the simulation process, and see how to import CAD-generated geometry and clean it up so that it’s ready for further pre-processing.

In today’s environment of 3D solid modeling, the simulation process often starts with geometry obtained from a CAD system. FEMAP can leverage and import the CAD model for most CAD systems and use it as a starting point to create the simulation model.

femap-cad-file-types

FEMAP is CAD neutral and can access CAD data from just about any source. It supports all major commercial CAD programs and data formats and kept up to date with the latest CAD product versions. Furthermore, Femap’s modeling engine is based upon the parasolid modeling kernel, which is the same as that used by Solidworks and Solid Edge.

In FEMAP, select the Import Geometry icon on the Model toolbar. Then select the geometry file you want to import. In this case, we will select geometry from a machine arm saved as a parasolid X_T transmit file.

The geometry scale factor shows the geometry units for this model. Since meters are the base units of length for parasolid, a value of 1000 indicates that we are using millimeters.

Click OK and the geometry is imported into Femap.

geometry-import

Once imported, we need to make sure that the geometry is in good shape. If any problematic geometry exists, it will adversely affect finite element mesh generation later on. In fact, identifying and cleaning up bad geometry is one of the biggest challenges in FE model creation and can take up valuable time.

In Femap, there are many tools available to help clean up the geometry, but in this example we’ll try the automatic approach.

Zooming into the model, we can see that there are indeed some extra points and curves present which will affect mesh generation.

We can select the geometry solid clean-up command and select the solid components, and we’ll just use the default clean up options.

With the successful execution of that command, we can see that the geometry has now been cleaned up.

geometry-cleanup

In the next section we’ll move on to the next stage and start to set up the model and define the materials, properties, and boundary conditions.