The Connection Type property specifies the joint as either a Body-Body scoping (multiple faces) or a Body-Ground scoping (multiple faces). When defined as Body-Body, you need to define Reference category and Mobile category properties. When you specify the Connection Type as body-to-ground, the application assumes that the reference element of the joint is grounded (fixed).

The Type property provides a drop-down list of joint type options. See the Specifying Remote Points section for descriptions of each type.

You use this property to specify a desired element type for the Bushing Joint. The options for this property include MPC (Multi-Point Constraint) and Bushing. These options enable you to specify the underlying element type for the Bushing Joint. The MPC option uses the MPC184 element and the Bushing option uses the COMBI250 element.

When you specify the Bushing option, the Element Coordinate System property also displays. As needed, specify a user-defined coordinate system. The default setting for this property is Reference Coordinate System.

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Important:  When you set the Formulation property to Bushing:

• The Element Coordinate System is the first coordinate system used to apply rotation.

• This is followed by nodal rotations defined on associated Remote Points (Reference or Mobile), such as the NROTAT command that rotates nodal coordinate systems into the active system. In addition, rotations from these remote points modify the element matrix (see the Input Data topic of the COMBI250 element reference).

• This is then followed by the normal processing sequence for rotations.

• Ansys recommends that you specify the same coordinate system for Element Coordinate System, Reference Coordinate System, and Mobile Coordinate System properties in case there is a relative rotation between the Element Coordinate System and either the Reference Coordinate System or Mobile Coordinate System. In addition, you need to verify proper rotation as well as results.

Here is an example of Element Coordinate System annotations ("rings" about each axis), prior to and after rotation.

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The Solver Element Type property enables you to specify the type of element to use in a fixed joint. Options include:

The Torsional Stiffness property defines the measure of the resistance of a shaft to a twisting or torsional force. You can add torsional stiffness only for cylindrical and revolute joints.

The Torsional Damping property defines the measure of resistance to the angular vibration to a shaft or body along its axis of rotation. You can add torsional damping only for cylindrical and revolute joints.

Includes or excludes the joint object in the analysis.

Element APDL Name: Optional property that enables you to manually define an APDL parameter (in the input file) and assign the parameter value as the element of the Joint. This facilitates easy programmatic identification of the element of the Joint for later use/reference in a Commands (APDL) object.

This property enables you to choose to scope using a Geometry Selection (default), Named Selection, or a user-defined Remote Point.

This property specifies the joint as a Remote Attachment (default) or a Direct Attachment. The Remote Attachment option uses either a user-defined or a system-generated Remote Point as a scoping mechanism. Remote Attachment is the required Applied By property setting if the geometry scoping is to a single face or multiple faces, a single edge or multiple edges, or multiple vertices. The Direct Attachment option enables you to scope directly to a single vertex (Geometry) or a node (using an individually selected node or a node-based Named Selection) for flexible bodies (only) on your model. Direct Attachment is not allowed if scoped to solid bodies, as they do not have rotational degrees of freedom.

Based on the selected Scoping Method, this property displays as either " Scope ", " Reference Component ", or " Remote Points ".

When Geometry Selection is selected as the Scoping Method, this property displays with the label " Scope " and enables you to define the geometry to which the joint is applied. Once a geometry is selected, click in the Scope field and then click Apply.

When Named Selection is selected as the Scoping Method, this property provides a drop-down list of available user-defined Named Selections.

When Remote Point is selected as the Scoping Method, this property displays with the label " Remote Points ". This property provides a drop-down list of available user-defined Remote Points. This property is not available when the Applied By property is specified as Direct Attachment.

This read-only property displays the corresponding part/geometry name.

The scoping of a joint must be accompanied by the definition of a joint coordinate system. This coordinate system defines the location of the joint. It is imperative that the joint coordinate system be fully associative with the geometry, otherwise, the coordinate system could move in unexpected ways when the Configure tool is used to define the initial position of the joint (see the Applying Joints section). A warning message is issued if you attempt to use the Configure tool with a joint whose coordinate system is not fully associative.

Under the Reference category, the Coordinate System property provides a default Reference Coordinate System. This coordinate system accompanies a joint when the joint is added to the tree. This applies for joints whose Connection Type is either Body-Ground or Body-Body. When a joint is added, an associated coordinate system is automatically generated at a location based on the selected geometry (face, edge, or vertex). You can modify the Reference Coordinate System’s orientation axis by modifying the details of the Reference Coordinate System object contained in the joint object.

Additional information about Modifying Joint Coordinate Systems is also available, including the following topics:

Scoping a joint directly to a vertex or a node using the Direct Attachment option fixes the coordinate system to that location. Note that the Reference Coordinate System property displays automatically and is read-only.

For remote attachments, use the Behavior property to specify the scoped geometry as either Rigid, Deformable, or Beam. If the Scope Method property of the Joint is set to Remote Point, the Joint will then assume the Behavior defined in the referenced Remote Point as well as other related properties. Refer to the Geometry Behaviors section for more information.

When the Behavior property is set to either Rigid or Deformable, you use this property to specify the contact algorithm used for a particular reference computation. If you set the Scope Method property to Remote Point, the Joint uses the Formulation defined for the Remote Point. Property options include:

For more information, see the Selecting a Contact Algorithm (KEYOPT(2)) topic in the Mechanical APDL Contact Technology Guide.

This property is only available when the Formulation property is set to MPC. You use this property to eliminate overconstraint present in the joint reference condition. Property options include No (default) and Yes. If you set the Scope Method property to Remote Point, the joint uses the setting of the Relaxation Method property defined for the Remote Point.

For more information, see the Overconstraint Detection and Elimination section of the Mechanical APDL Contact Technology Guide.

Use the Pinball Region property to define where the joint attaches to face(s) if the default location is not desirable. By default, the entire face is tied to the joint element. This may not be desirable, warranting the input of a Pinball Region setting, for the following reasons:

This property enables you to choose to scope using a Geometry Selection (default), Named Selection, or a user-defined Remote Point.

This property specifies the joint as a Remote Attachment (default) or a Direct Attachment. The Remote Attachment option uses either a user-defined or a system-generated Remote Point as a scoping mechanism. Remote Attachment is the required Applied By property setting if the geometry scoping is to a single face or multiple faces, a single edge or multiple edges, or a single vertex or multiple vertices. The Direct Attachment option allows you to scope directly to a single vertex (Geometry) or a node (using an individually selected node or a node-based Named Selection) to flexible bodies (only) on your model. Direct Attachment is not allowed if scoped to solid bodies, as they do not have rotational degrees of freedom.

Based on the selected Scoping Method, this property displays as either " Scope ", " Mobile Component ", or " Remote Points ".

When Geometry Selection is selected as the Scoping Method, this property displays with the label " Scope " and enables you to define the geometry to which the joint is applied. Once a geometry is selected, click in the Scope field and then click Apply.

When Named Selection is selected as the Scoping Method, provides a drop-down list of available user-defined Named Selections.

When Remote Point is selected as the Scoping Method, this property displays with the label " Remote Points ". This property provides a drop-down list of available user-defined Remote Points. This property is not available when the Applied By property is specified as Direct Attachment.

This property is available under both the Reference and Mobile categories. This read-only property displays the corresponding part/geometry name.

The Mobile category provides the support for the relative motion between the parts of a joint. A Mobile Coordinate System is automatically defined but is only displayed in the tree when the Initial Position property is set to Override.

Scoping a joint directly to a vertex or a node using the Direct Attachment option fixes the coordinate system to that location. When scoping directly to a node or vertex using the Direct Attachment option, the default setting for the Initial Position property is Override even though the Initial Position property doesn't display in the Details. Rather, the Coordinate System automatically displays and is read-only.

This property applies to remote attachments only (direct attachments fix the coordinate system). It provides a drop-down list with the options Unchanged and Override. The Unchanged option indicates the use of the same coordinate system for the Reference category and the Mobile category and the Override option causes a Coordinate System property to display in the Mobile category with the default setting Mobile Coordinate System.

For remote attachments, use the Behavior property to specify the scoped geometry as either Rigid, Deformable, or Beam. If the Scope Method property of the Joint is set to Remote Point, the Joint will then assume the Behavior defined in the referenced Remote Point as well as other related properties. Refer to the Geometry Behaviors section for more information.

When the Behavior property is set to either Rigid or Deformable, you use this property to specify the contact algorithm used for a particular reference computation. If you set the Scope Method property to Remote Point, the Joint uses the Formulation defined for the Remote Point. Property options include:

For more information, see the Selecting a Contact Algorithm (KEYOPT(2)) topic in the Mechanical APDL Contact Technology Guide.

This property is only available when the Formulation property is set to MPC. You use this property to eliminate overconstraint present in the joint mobile condition. Property options include No (default) and Yes. If you set the Scope Method property to Remote Point, the joint uses the setting of the Relaxation Method property defined for the Remote Point.

For more information, see the Overconstraint Detection and Elimination section of the Mechanical APDL Contact Technology Guide.

For remote attachments, use the Pinball Region property to define where the joint attaches to face(s) if the default location is not desirable. By default, the entire face is tied to the joint element. This may not be desirable, warranting the input of a Pinball Region setting, for the following reasons: