Using Part Contact Data to Create Interfaces

A geometry part has a Contacts property that provides a list of all other parts with which the part is in contact. This part contact data can be used to generate interfaces for meshing and physics coupling automatically without having to create and assign coincident faces manually.

The two key steps in successfully obtaining interfaces are to:

Generate part contact data using an appropriate method.
Assign parts to regions in the correct manner.

Using this procedure is useful when you have lots of parts that are in contact with each other and want to produce a conformal mesh at the interface of each part. This procedure requires you to use the surface remesher with the tetrahedral or polyhedral volume meshers.

Generating Part Contact Data

Part contact data can be obtained through the following routes:

For CAD parts, if the original parts are imprinted on their adjacent neighbors before being imported, select the Create Part Contacts from Coincident Entities option on the Surface Import Dialog.

This option causes Simcenter STAR-CCM+ to detect the coincident faces that are within the specified Coincident Face Tolerance automatically and create corresponding part contacts. For 3D-CAD models, this option is used internally when converting them to 3D-CAD parts. See the section, Creating Part Contacts From Coincident Entities for more information.
The imprint mode of the Surface Preparation Tool can be used to generate coincident part surfaces and associated part contacts.

This facility is available for all part types, including surface mesh parts and inherited part surfaces. An example of the procedure is given below in section, Imprinting Parts on their Neighbors.
The Find Part/Part Contact... menu action can be used to run a proximity analysis that detects adjacent parts.

This action does not imprint neighboring parts: imprinting happens during the surface and volume meshing process, which can only take place after the parts have been assigned to regions. Further information is given in section, Finding Part Contacts Automatically.
It is also possible to create part contact data manually, either by using the Create Part/Part Contact menu item or by populating node properties directly.

A part contact browser is provided to give easy visualization of the parts that are in contact.

Assigning Parts to Regions

It is crucial that all parts are assigned to new regions in a single operation.

To assign parts to regions:

Select all parts in the object tree using <Ctrl><Click> or <Shift><Click>.
Right-click and choose Assign Parts to Regions...
The Assign Parts to Regions dialog appears.
In the Assign Parts to Regions dialog, select the appropriate Region Mode and Boundary Mode.
For information on the available options, see Table of Valid Methods and Options.
Select the method by which the interfaces are formed. The options available are:
- Create Boundary-mode Interfaces From Contacts
- Create Contact-mode Interfaces From Contacts
For more information on these options, see Interfaces Overview.

Table of Valid Methods and Options

The table below summarizes the routes for generating part contact data, and gives the valid options that can then be used when assigning parts to regions using the Assign Parts to Regions dialog.


Status of original parts	Relevant Routes for Creating Part Contact Data	Valid Part Types for Route	Valid Options for Region Assignment
Status of original parts	Relevant Routes for Creating Part Contact Data	Valid Part Types for Route	Region Mode	Boundary Mode
Neighboring parts that are already imprinted	Activate the Create Part Contacts from Coincident Entities option when importing. For 3D-CAD parts, this option is always activated internally when converting models to parts	CAD and 3D-CAD only	One region for all parts	One boundary per part surface
			One region per part	One boundary for all part surfaces
			One region per part	One boundary per part surface
Neighboring parts that are not imprinted	Manually imprint parts using the Imprint mode of the Surface Preparation Tool	All part types	One region for all parts	One boundary per part surface
			One region per part	One boundary for all part surfaces
			One region per part	One boundary per part surface
	Select the Find Part/Part Contacts... menu action	All part types	One region per part	One boundary for all part surfaces
	Manually define part contact data	All part types	One region per part	One boundary for all part surfaces

Example Process

The steps below illustrate the process of how interfaces are generated from part contact data.

(1) Part contact information is stored on each body

(2) Parts are assigned to new regions (in a single operation)

The result of this operation is the creation of two new regions and an interface for the contact between the regions.