NURBS Retransition - Mesh to CAD

The Mesh to CAD functionality is transitioning the optimisation result from an STL-file back into a NURBS-Geometry. Therefore, a surface quad mesh is modelled on the optimisation result geometry and patches for bigger planar surfaces are merged intelligently.

The Retransition should be performed on a non-intersected, smooth optimisation result. For this the smooth geometry can be transferred from the Post Processing to the model tree with the transfer-button.

The geometry of this file always stays within the Design Space limits except for the Interface areas, they intentionally exceed the Design Space limits to enable an easy and clean Boolean intersection. After the Retransition the intersection with the Design Space should be done to create all functional surfaces and sharp edges.

The workflow to achieve this transition is as follows:

1. Transfer a smooth (non-intersected) optimisation result to the model tree.

2. Create a NURBS CAD geometry with the Facet to NURBS Tool (Geometry Edit Tools).

   1. Let the software determine a suitable Quad-mesh size.

   2. Choose your own suitable Quad-mesh size.

3. Sometimes the NURBS are not fully generated. Status message: Failed to create 2 out of 14,000 faces.

   1. Use the Geometry Cleanup Tools.

   2. If necessary, use the Filler Tool to restore missing NURBS-Patches.

4. Boolean Intersection between the NURBS-Geometry and Design Space either in MSC Apex Generative Design or MSC Apex.

This workflow can be executed automatically with a custom tool. How to use it here.

The resulting NURBS-Geometry can be manipulated by MSC Apex (Generative Design) or any CAD software. The Retransition ensures and simplifies the continuing workflow to the FE-Reanalysis, further CAD modification and process simulation.

You might also be interested in these tutorials:

• NURBS Retransition Full Workflow

• NURBS Retransition - Manual Geometry Cleanup