Contacts in Creo Ansys Simulation
Creo Ansys Simulation enables you to create contacts between references within your model either manually or automatically. You can create contacts between surfaces, edges, and vertices. The way that the references in contact behave (staying connected, sliding, or separating) during a simulation study is called contact behavior.
For a thermal study you can create thermal contact behavior to account for the conductive heat transfer between surfaces in contact. You can create contacts within your model using the following methods:
Automatically Detect Contacts when Defining a New Simulation Study
When you create a new simulation study the Use automatic contacts detection check box is selected by default. The software detects all the surfaces between solid bodies that are within a predefined distance of each other. Contacts detected using this method are automatically assigned a bonded contact behavior and available on the Simulation Tree under the Contacts node and the Bonded sub-node for the simulation study. You can edit or remove the contacts as required. Note that self contacts (contacts within the same body or component, or a curved surface curving onto itself) are not detected using this method and this page is not displayed for single body models. Contacts between non-solid references are also not detected with this method.
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If the model geometry changes after creating a study with the Use automatic contacts detection check box selected, you can use the command >  Contact > to detect all contacts in that study again as new contacts may be introduced, or the previously detected contacts could be out-of-date, or no longer valid. |
Automatically Detect Contacts by Selecting References
The software can also automatically detect contacts between two or more selected solid bodies or components that are within a specified distance from each other for the active simulation study.
To automatically detect contacts in your model for an active simulation study perform the following steps:
1. Click > Contact > . The Auto-Detect Contacts dialog box opens.
Contact > . The Auto-Detect Contacts dialog box opens.2. Select solid components or bodies in the model. Your selections are displayed in the References collector.
3. The Tolerance box displays a default value that is automatically calculated based on the model geometry. Change this value to specify the distance within which you want to detect contacts. Click 
if you want to revert to using the default value.
if you want to revert to using the default value.4. Select one of the following options for Contact behavior:
◦ Bonded—There is no separation or sliding allowed between references that are in contact. Bonded contacts have zero degrees of freedom between interfacing components and can be considered as glued together. Bonded components do not separate from each other during a simulation study. This type of contact allows for a linear solution since the contact length or area does not change during the application of the load.
◦ No Separation—Similar to bonded contacts, separation of the references in contact is not allowed during a simulation study. However small amounts of frictionless sliding can occur along references in contact.
This option is not available for thermal studies.
◦ Free—The connected components or surfaces may move freely relative to each other. The components may separate from each other or even interpenetrate each other. The applied forces do not transfer between the connected components or surfaces.
◦ Frictionless—This setting models standard unilateral contact; that is, normal pressure equals zero if separation occurs. Thus gaps can form in the model between bodies depending on the loading. This is a nonlinear case, because the area of contact may change as the load is applied. This option assumes a zero coefficient of friction allowing free sliding. The model should be well constrained when using this contact setting.
◦ Rough—This setting models perfectly rough frictional contact where there is no sliding between edges or surfaces. By default, no automatic closing of gaps is performed. This case corresponds to an infinite coefficient of friction between the contacting bodies.
◦ You can also select a previously created contact behavior from the Contact behavior list or select Create new from the Contact behavior list if you want to define a custom contact behavior. Specify a name for the contact behavior or use the default.
5. Select the Override Behavior for existing contacts check box to switch the behavior of existing contacts to use the currently selected behavior.
6. For models containing shell pairs select the Create one to one reference contacts check box..
7. Click OK. Contacts that meet the specified tolerance criteria are created and appear under a contact behavior sub-node of the Contacts node in the Simulation Tree.
Creating Contacts Manually
You can manually create contacts between two references in your model . To create a contact manually perform the following steps:
1. Click > Contact.
Contact.2. The Contact Definition dialog box opens.
3. Specify a name or use the default. Optionally, click the color swatch adjacent to the Name box to change the color of the icon, the distribution, or the text displayed.
4. Select a surface, an edge, a curve, or a vertex in the First reference collector.
5. Select a surface, an edge, a curve, or a vertex in the Second reference collector.
| | You can create contacts for the same reference by selecting the same reference in both the First reference and the Second reference collectors. |
6. Select one of the following options for Contact behavior:
◦ Bonded—There is no separation or sliding allowed between references that are in contact. Bonded contacts have zero degrees of freedom between interfacing components and can be considered as glued together. Bonded components do not separate from each other during a simulation study. This type of contact allows for a linear solution since the contact length or area does not change during the application of the load.
◦ No Separation—Similar to bonded contacts, separation of the references in contact is not allowed during a simulation study. However small amounts of frictionless sliding can occur along references in contact.
This option is not available for thermal studies.
◦ Free—The connected components or surfaces may move freely relative to each other. The components may separate from each other or even interpenetrate each other. The applied forces do not transfer between the connected components or surfaces.
◦ Frictionless—This setting models standard unilateral contact; that is, normal pressure equals zero if separation occurs. Thus gaps can form in the model between bodies depending on the loading. This is a nonlinear case, because the area of contact may change as the load is applied. This option assumes a zero coefficient of friction allowing free sliding. The model should be well constrained when using this contact setting.
◦ Rough—This setting models perfectly rough frictional contact where there is no sliding between edges or surfaces. By default, no automatic closing of gaps is performed. This case corresponds to an infinite coefficient of friction between the contacting bodies.
◦ You can also select a previously created contact behavior from the Contact behavior list or select Create new from the Contact behavior list if you want to define a custom contact behavior. Specify a name for the contact behavior or use the default.
7. Click OK to create the contact. Click Repeat to save the current contact and open the Contact Definition dialog with the same options already selected or entered.
Creating Contact Behavior for Thermal Studies
To consider the conductive heat transfer between surfaces in contact, you can specify the thermal contact conductance for a contact behavior. Thermal contact conductance must have a value greater than 0. You can create a contact behavior up-front and use it when defining contacts later.
Perform the following steps to create a thermal contact behavior:
1. Click > > . The Thermal Contact Behavior dialog box opens.
2. Specify a name for the contact or accept the default name.
3. Specify a positive value, a parameter, or an expression that evaluates to a positive value for Conductance. Select units for conductance.
4. Click OK to create and save the contact behavior. The contact behavior is displayed in the Simulation Tree and is the parent node of any contacts that use it.