| 1. | Die exit (Profile): Place four free nodes between the opposite walls (profile thickness). Same guidelines apply for steady and transient analysis. |
| 2. | Bearing Region: Use a constant element length in the flow direction. General rule is to use four elements to represent smallest bearing length. This allows the program to predict accurately flow at the die exit. |
| 3. | Profile section: Length of the profile section should be approximately smallest of: |
| • | 5 – 7 times the maximum bearing length or, |
| • | 5 – 7 times the maximum wall thickness |
| 4. | Use triangular prism/brick elements in the bearing and profile regions. |
Mesh Generation Steps
| 1. | Create solid volumes of different components (billet, portholes, weld chamber, bearing, backer, bolsters, mandrel, …) |
| 2. | Use volume tetrahedral elements meshing option to create tet mesh. |
| 3. | Start with the bearing region first. Next generate mesh in other components - weld chamber, portholes, billet, …) This allows you to create meshes with small element size in regions close to the die exit. |
| 4. | Make sure the elements meet the following criteria: |
| • | Max. aspect ratio: TET4 < 8, PENTA6 <12, PYRAMID5 < 12 ; HEX8 <25 |
| • | Min. value for “tet collapse” for elements in portholes and weld chamber is > 0.2 |
Mesh for Tool Geometry
| 1. | Meshes at the tool-work piece interface need to match. For example; |
| • | When generating mesh in container, you can maintain the same radial mesh density for both billet and container. The mesh along the billet/container length does not need to match. You can use a coarse mesh for container. |
| • | Similarly, the meshes on die face from tool side can be different from the work piece mesh. |
| 2. | The only exception for this is in regions where the geometry curvature plays an important role (portholes, mandrel walls, bearing region). Here the mesh densities must be such that nodes of elements from one side (ex: tool) should not penetrate the elements on the opposite side (work piece). |
See Also:
Guidelines for Simulation
