In ANSYS Workbench, the contact relationship between bodies or parts is defined through the Mechanical component. There are generally three ways to define contact: automatic contact recognition, manual contact definition, and automatic contact recognition through grouping.
Method 1: Defining contact through automatic contact recognition
The contact relationship between bodies or parts can be automatically detected and created during the process of importing the geometry model into Mechanical. This can be achieved by setting the “Auto Detect Contact On Attach” option in the “Mechanical” tab under the “Options” dialog box, as shown in the figure below.
When using Mechanical to automatically recognize contact relationships, a series of “Contact” directories will be automatically created under the “Connection” branch. Each “Contact” directory contains multiple contact regions that have been identified by the software.
Each contact region includes the contact and target sides, which are the two surfaces on either side of the contact interface. When selecting a contact pair in the Project tree, the contact and target surfaces will be displayed in red and blue colors respectively in the graphical display area, while the bodies or parts that are not related to the selected contact pair will be displayed in a translucent manner by default.
As shown in the figure on the left below, the geometry model consists of three parts. When selecting the contact region between the lower disk and the middle block, the contact surface is displayed as shown in the figure on the right. The upper block is not related to this contact region and is therefore displayed in a translucent manner.
By selecting the “Body Views” button on the toolbar, the Body View view can be opened, which allows for a clearer observation of the two sides of the contact surface and the location of the contact surface, as shown in the figure below.
In the Body View view, the part on the target side is displayed in a translucent manner in the view of the contact side, and vice versa in the view of the target side.
Method 2: Manual contact definition
Even if the automatic contact detection option is selected in the Workbench Options, the contact relationship can still be manually defined after importing the model. The key points for manual contact definition are as follows:
（1）Right-click the Connection branch in the Project tree, select Insert > Manual Contact Region, as shown below. This will add a new Contact branch under the Connection directory, and a new manual contact pair branch will appear under the new Contact branch.
（2）Select the newly added contact pair branch, and manually select the contact and target surfaces in its Details to complete the contact definition.
Method 3: Automatic detection with grouping
If contact is not automatically detected during the import of the geometry model into the Mechanical component, contact can still be automatically detected between some bodies after the import is complete. This method can be understood as a partial automatic contact recognition, and is a more practical way to operate. The key points for operation are as follows:
（1）First, select the bodies for which contact needs to be recognized, then select the Connection branch in the Project tree, and select Insert > Connection Group in its right-click menu, as shown below. This will create a Connection Group directory under the Connection directory.
（2）Define the automatic detection options.
In the Connection Type field, the default is Contact, which is used for contact detection. The Geometry option under the Scope field lists the number of selected bodies. The Auto Detection section is used to set up automatic contact detection. The Tolerance field is used to set the tolerance for the contact detection distance. The Use Range and Tolerance options can be used together to further narrow down the contact detection distance. The three options of Face/Face, Face/Edge, and Edge/Edge are used to specify whether to include this type of contact. The Priority option is used to specify the priority level of contact detection, as shown below. If Face Overrides is selected, face-to-face and face-to-edge contacts are prioritized, and edge-to-edge contacts may not be detected. If Edge Overrides is selected, edge-to-edge and face-to-edge contacts are prioritized, and face-to-face contacts may not be detected.
（3）Automatic contact detection.
Select Create Automatic Connections in the right-click menu of the Connection Group branch, as shown below. Mechanical will automatically search for contact relationships between the relevant bodies.
After the search is complete, the Connection Group is automatically renamed to Contacts branch, and the Contact Region branches that were detected according to the set conditions are listed under this branch, as shown below.
Regardless of the method used to create contact, relevant properties need to be defined for each Contact Region, which can be set through the Details of each contact branch. A future article will be published to introduce contact option settings.