Interfaces
Several interfaces are available in Radioss, this section deals with contact interfaces only. Each interface is distinguished with a type number.
Interface TYPE2 is a kinematic condition used to connect two Lagrange meshes and is not detailed in this section (refer to Kinematic Constraints). A brief overview of the contact interfaces are shown in Table 1.
Each of these interfaces was developed for a specific application field, but this field is not the only choice criteria. Some limitations of the different algorithms used in each interface can also determine your choice.
The algorithm limitations mainly concern the search of the impacted segment. This search can be done directly (interface TYPE7, TYPE10 and TYPE11) or via the search of the nearest node (other interface types). The nearest node search is done with a cheap, but limited algorithm (interface TYPE3, TYPE5 and TYPE6).
Interface TYPE3, TYPE5 and TYPE6 also have some limitations concerning the choice between the segments connected to the nearest node. Normal orientation is one limitation for these interfaces.
Interface TYPE23 defines a contact interface for airbag fabrics. This is a soft penalty contact which can deal with penetrations and intersections often coming in the folded airbag mesh.
Interface TYPE24 use constant penalty stiffness and therefore the time step is not affected.
| Type | Description | Application | Contact Treatment |
|---|---|---|---|
| 1 / 9 | ALE/LAG with sliding | Fluid-structure interaction | Master-Slave |
| 2 | Tied interface | Change of mesh density (solid) | Master-Slave or LM |
| 3 & 5 | Contact impact between two parts | Use of TYPE7 is recommended | Penalty |
| 6 | Contact impact between two rigid bodies | User-defined contacts | Penalty |
| 7 | General purpose contact impact between two parts | Solid contact impact at all speeds | Penalty or LM |
| 8 | Drawbead contact | Stamping applications | Penalty |
| 10 | Like TYPE7, but tied contact | Special purpose interface | Penalty |
| 11 | Impact between two lines | For beams, bars or springs | Penalty |
| 12 | Fluid / fluid contact | Fluid to fluid contact | Penalty |
| 16 & 17 | Contact between nodes to quadratic shape solids and solid-shells or between quadratic shapes | Meshes with 8-node or 16-node thick-shell or 20 bricks | LM |
| 18 | CEL Lagrange / Euler interface | Fluid-structure interactions | Penalty |
| 19 | Combination of interface TYPE 7 and TYPE 11 | Solid contact impact at all speeds and For beams, bars or springs | Penalty |
| 21 | Specific interface between a non-deformable master surface and a slave surface | For stamping | Master-Slave |
| 23 | Soft penalty contact | For airbag | Soft penalty |
| 24 | General contact interface, optional single surface or surface to surface or nodes to surface contacts | This contact interface can replace interface TYPE3, 5, 7 | Penalty stiffness is constant and therefore the time step is not affected |