Pre-nesting Manufacturing Profiles - Intergraph Smart 3D - Help - Hexagon

If the manufacturing type is set to Pre-nesting, you can select a light or detailed part for manufacturing. The software uses the same manufacturing process for both light and detailed pipes with the following exceptions:

Using Light Part

In production nesting, the software uses the detailed profile part to retrieve landing curve and end-cut feature information. When Smart 3D details a part, it trims that part to the bounding structure. This means that the software trims the landing curve to the bounding elements. The landing curve is extended to the extreme range of the feature, and the end-cut features are imposed on the unfolded feature solid. The software gets the contour information for the web and flange from the resulting Boolean solid.

With Pre-nesting, the software uses the light part to get the landing curve information. Because of this, the contours are not trimmed to the bounding elements, and there are no end cuts applied on the profile part ends.

Using Logical Connections

Production nesting uses physical connections to retrieve the bevel information from the model and carry that information to the edge. With pre-nesting, the software stores the logical connections in the manufacturing bevel objects.

Bevel Offset Correction Calculation

In production nesting, the software extends the landing curve beyond the profile solid and trims the ends by feature cuts. This technique also assigns physical connection and corresponding bevel properties to the resulting edge. In the post-processing stage after unfolding, the software computes bevel offsets for each edge and makes necessary corrections by offsetting the contour curve according to the bevel properties.

In pre-nesting, the software always calculates bevel offset correction for every contour edge to the long point using the following algorithm. This algorithm is used for both light and detailed parts.

1. Get the landing curve end point at the given end.

2. Get the profile cross section orientation vectors ( X and Y ) at the end. Evaluate the Z-direction by crossing the X and Y vectors.

3. Set the Z-direction as the material direction that points towards the material side of the profile part.

   

   1. Bounding Plate Parts
   2. Light Profile Part shown in web left plane
   3. Material Direction
   4. Material Direction
   5. Supporting Plate
   6. Landing Curve

4. Create a plane at the landing curve end point with the Z vector as the plane normal.

5. Intersect this plane with the profile part geometry (before any feature cuts are applied ) to get the edges corresponding to the cross section shape.

6. Get all of the start points of the previous edges. These points represent the vertices of the cross section at a given position.

   

   1. Cross section plane at the end of the landing curve
   2. Vertex Points

7. Get the logical connection from the face port and the connected ports and connected structural plate or profile parts.

8. Get all of the ports of the bounding plate or profile part.

9. For each face port in the port collection:

   • Check the direction of the port surface. If the port surface is not pointing towards the material direction, the software does not use this surface.

   • Project each cross section vertex point, which is calculated above, onto the bounding surface in the material direction.

     • For plates, the software projects the point onto the base and offset surfaces.

     • For profiles, the software projects the point onto all lateral faces except base and offset end caps.

       

       1. Bounding surfaces upon which the software projects the vertex points

   • Verify whether the point is projected towards the material direction or away from the material direction.

   • If the point is projected towards the material direction, the software takes the closest bounding point and calculates the negative bevel offset correction value.

   • If the point is projected away from the material direction, the software takes the farthest bounding point and calculates the positive bevel offset correction value.

10. Store the bevel offset value in the manufacturing bevel object. The software then uses that bevel object to make the bevel correction in the post-processing stage.

    

    1. Manufacturing Profile Shape
    2. Profile Length

Feature Cuts

In production nesting, Smart 3D applies feature cuts after unfolding the profile parts. In pre-nesting, the software does not apply feature cuts.

Margins and Shrinkages

In both production nesting and pre-nesting, Smart 3D applies margins and shrinkages on the profile part. There are no changes in this functionality.

Handling Free End Cuts

When a profile part is detailed in Structural Detailing, the software automatically runs the detailing rules to generate free end cuts at the free ends (ends which are not bounded by structure). In the production nesting solution, the software extends the landing curve and places end-cuts on the profile end. This reduces the profile length according to the end cut feature dimensions. In some situations, end cuts extend the profile part beyond the supported surface of the profile.

In pre-nesting, the profile is not detailed and end-cuts are generated by default. Because of this, the profile length reported in pre-nesting is greater than the value reported in production nesting in most free end cases.