Bearing / Bushing / Damper / Spring Connection dialog box

General page

Physicals Definition
Available for bushing connections.Sets the type of coordinate system used to define stiffness and damping properties on theConstant Physicals and Dynamic Physicals pages.
Rectangular	Defines stiffness and damping properties using a rectangular coordinate system with components in the X, Y, and Z directions.
Cylindrical	Defines stiffness and damping properties using a cylindrical coordinate system with components in the R and Z directions.Note: To include components of stiffness and damping with respect to a cylindrical coordinate system in your analysis, you must:Set Rotor Dynamics as the specified analysis type.Realize (mesh) the bushing connection using the CBUSH2+RBE2 spider(s) element combination.When you realize (mesh) the connection using CBUSH2+RBE2 spider(s), a PBUSH2 property is created and assigned to the CBUSH2 element, which contains the defined stiffness and damping properties.
Name
Name	Sets the name of the connection. After you create the first connection, the software numbers the connections sequentially starting with 1. You can either use this default name or provide a new name.
Description	Sets a description for the connection.To manage the text, you can use the Cut , Copy , and Paste commands. This description appears in the Description column in the Simulation Navigator.
Folder
Specifies the folder in the Universal Connections container where you want to save the connection. Using folders helps you to effectively manage a large number of connections.
Select Folder	Opens the Folder Selector dialog box, which lists the folders in the Universal Connections container. You can specify the destination folder for your connection from here.

Targets page

The following table shows the possible combinations between the target types.

	Target 2****Single Point	Target 2****Set of Points	Target 2****Spider	Target 2****Local Spider
Target 1****Single Point
Target 1****Set of Points
Target 1****Spider
Target 1****Local Spider

Target 1 / Target 2
Single Point	Lets you select a single mesh point, a single mesh node, or selection recipe as your target entity.Note: If you plan to create a bearing connection by defining both Target 1 and Target 2 using Single Point and then realize (mesh) the connection using CBEAR2 + FOU3 + RBE3 spider(s) element combination:Target 1 must be defined on the rotor axisTarget 2 must be collinear with Target 1 such that Target 1 and Target 2 are perpendicular to the 2D rotor axis.When you realize (mesh) the connection, the software does not create RBE3 elements.
Set of Points	Lets you select a set of points on Target 1 and Target 2 from any combination of geometric (point, edge, face, body) objects, finite element (node, edge, face, element, mesh) objects, or selection recipes that can return nodes. The connection element is created by searching the pairs of nodes to be connected using one of the following methods:ProximityOriented searchSelection orderNote: If you plan to create a bearing connection by defining both Target 1 and Target 2 using Set of Points and then realize (mesh) the connection using CBEAR2 + FOU3 + RBE3 spider(s) element combination, the software does not create RBE3 elements.
Spider	Lets you select an RBE2 spider center as one of the targets. For more information on RBE2 spider elements, see Working with RBE2 and RBE3 spider elements.For the center, you can let the software calculate it, or you can select a mesh point, mesh node, point, or selection recipe.For the legs, you can select any combination of geometric (point, edge, face, body) objects, finite element (node, edge, face, element, mesh) objects, or selection recipes that can return the nodes to use in the spider legs.
Local Spider	Lets you create a target that consists of a main spider whose legs connect to other spiders, called local spiders. The main spider has a main center, and its main legs become the local centers of the spiders that connect to it. Use the Local Spider target to connect multiple objects in the target. Local Spider target with (1) local legs, (2) local centers / main legs, (3) main centerFor more information on local spiders, see Local spider element targets in universal connections.
Single Point Selection
Appears when the target is set to Single Point.
Select Object	Lets you select the geometric or finite element objects to set them as targets.
Node Label	Type a node label and click to select the node.
Set of Points Selection
Appears when the target is set to Set of Points.
Select Objects	Lets you select the geometric or finite element objects to set them as targets.
Method of Connection
Appears when Set of Points is selected.These options define the pair of target nodes to create a connection element.
Proximity	Lets you set a search range that defines the maximum permissible distance between the nodes of the first target group and the nodes of the second target group for an acceptable target node.
Oriented Search	Lets you set options to form a search cone based on which nodes of the two target groups are paired.For each node in the first target group, the software finds the closest node in the second target group within the search cone and pairs them if the distance between them is less than or equal to the search range.
Specify Vector	Appears when Oriented Search is selected.Lets you specify the orientation vector that defines the direction of search.Click Vector Dialog to open the Vectordialog box. You can define the orientation vector here. For more information see, Vector dialog box.Click to choose a vector command to define the orientation vector.Click to reverse the direction of the orientation vector.
Selection Order	Pairs the target nodes based on the order in which you select them in the graphics window.
Proximity Search Definition
Appears when Proximity is selected as the method of connection.
Search Range	Sets the maximum permissible distance between the nodes of the first target group and the nodes of the second target group for an acceptable target node.For each node in the first target group, the software finds the closest node in the second target group and pairs them if the distance between them is less than or equal to the search range.
Search Cone Definition
Appears when Oriented Search is selected as the method of connection.
Cone Angle	Defines the maximum permissible angular deviation from the direction of search for an acceptable target node.
Search Range	Defines the maximum permissible distance between the nodes of the first target group and the nodes of the second target group for an acceptable target node.
Center Selection
Appears when Spider is the selected target.
Use Legs' Center of Gravity	Sets the center of the spider to the center of gravity of the spider legs.Note: When you manually select the spider center, the software saves your selection. Thus, you can switch to using Use Legs' Center of Gravity. When you switch back, the spider center you originally selected is still selected.
Select Object	Appears when Spider is the selected target and the Use Legs' Center of Gravity check box is cleared.Lets you select a mesh point, a mesh node, a point, or a selection recipe as the spider center.Note: Selection recipe selection is limited to entities that resolve to a single node (that is, single label, coordinate, or point). Selection recipes that resolve to other types of entities are automatically removed from the selector and a warning message appears.To create a point for the spider center, click Create New Point .
Node Label	Type a node label and click to select it as the center.
Legs Selection
Appears when Spider is the selected target.
Select Objects	Lets you select the spider leg locations with any combination of geometric (point, edge, face, body) objects, finite element (node, edge, face, element, mesh) objects, or selection recipes that can return nodes.
Center
Appears when Local Spider is the selected target.
Use Mean Coordinates of Leg Locations	Computes the center of the main spider as the mean of the location coordinates of the legs that are added to the Legs Location list.
Select Object	Appears when Local Spider is the selected target and the Use Mean Coordinates of Leg Locations check box is cleared.Lets you select a mesh point, a mesh node, a point, or a selection recipe as the main spider center. Note: Selection recipe selection is limited to entities that resolve to a single node (that is, single label, coordinate, or point). Selection recipes that resolve to other types of entities are automatically removed from the selector and a warning message appears.To create a point for the local spider center, click Create New Point .
Node Labels	Type a node label and click to select it as the center.
Leg Locations
Appears when Local Spider is selected.The leg locations are coordinates on the target that you want the main spider to connect to. The software may not use all of the leg locations depending on the value you set for Max. Search Distance. For example, if a leg location is within the radius set by Max. Search Distance, that location becomes a leg. Otherwise, the leg connection is marked as failed, and you must remove that leg location to make the universal connection valid.
Select Objects	Lets you select the local spider leg locations with any combination of geometric (point, edge, face, body), finite element (node, edge, face, element, mesh) objects, or selection recipes that can return nodes. Select the locations on the target you want to connect to. The leg locations you add are listed in the table. When you click OK or Apply to create the rigid or kinematic connection, the Info column updates to indicate whether each leg location succeeded or failed at connecting to the connection target. The rigid or kinematic connection is invalid until you delete the failed leg locations. To delete a location, select it and click Delete .
Connection Target
Appears when Local Spider is selected.
Select Objects	Lets you select object types such as elements, element faces, meshes, polygon bodies, polygon faces, or a selection recipe as the regions of the model for the local spider legs to connect to. For example, if you want to connect a body to a sheet with holes, the sheet with holes is the connection target for the local spider. You can select the polygon face, or you can select the edges around the holes.
Target Detection
Appears when Local Spider is selected.
Max. Search Distance	Sets the maximum search radius around each leg location on the connection target. The closest node within each search radius becomes the reference point for the remaining local spider options.If the closest node to the leg location is the free inner edge of a 2D mesh, the software automatically creates legs around the circle.If the closest node to the leg location is the leg location, the software creates a spider leg at that location.
Connect Spiders To
Appears when Local Spider is selected.
Nearest Selected Target	Computes the local spider using only the closest nodes on the connection target that are within the Max. Search Distance radius.
All Selected Targets	Connects the legs of the local spiders to the nodes on each connection target when the following conditions are met:The distance between the closest node (relative to the leg location) and the leg location is less than or equal to the value set by Max. Search Distance. The distance between the closest node (relative to leg location) and the closest node (relative to leg location) of the closest target (that is, the reference point) is less than or equal to the value set by Target Search Range.
Target Search Range	Appears when All Selected Targets is selected.Sets the range within which the software searches for nodes on the connection target. For a target to be selected, the distance from its closest node (or hole center if a hole is detected) to the closest node (or hole center if a hole is detected) of the closest target must be smaller than the specified search tolerance.
Ring Options
Appears when Local Spider is selected. For each of these ring options, the center of the local spider is computed as the center of gravity of the leg nodes.Note: If more than 100 nodes are found, the visualization changes to show the center of gravity of the legs with an annotation that displays the number of nodes.
1 Ring	Connects the legs of the local spiders to the nodes of the free edges of the hole (if detected). If a hole is not detected, a single spider leg is created.
2 Rings	Connects the legs of the local spiders to the nodes of the free edges of the hole (if detected) and also to the nodes of the first layer of elements around the hole. If a hole is not detected, a single spider leg is created.
Expansion Radius	Connects the legs of the local spiders to all of the nodes within the range specified by this radius. The radius is around the closest node to the legs locations.
Expansion Radius Factor	Connects the legs of the local spiders to all of the nodes within the range determined by multiplying the expansion radius factor with the radius of the hole (that is, the distance between the center of the hole center and the node that is closest to that center). The expansion radius is determined as follows:D = Rmin * Fwhere:D is the search range.Rmin is the radius of the hole (the distance between center of the hole and the closest node).F is the value you enter for Expansion Radius Factor.These nodes are used to create or remove legs from the local spiders, depending on whether the value for Expansion Radius Factor increases or decreases the search radius. If no hole is detected, one leg is created from the leg location to the node found in the radius computed by the Expansion Radius Factor.

Axis Type page

Axis Type
Specifies an axis to be considered with respect to which the various physical spring and damping parameters are defined.
Existing	Sets the coordinate system to the coordinate system attached to the FEM model.
Absolute	Sets the coordinate system to the absolute coordinate system.
Cartesian	Sets the coordinate system to a new Cartesian coordinate system.
Cylindrical	Sets the coordinate system to a new cylindrical coordinate system.
Spherical	Sets the coordinate system to a new spherical coordinate system.
Specify CSYS	Click CSYS Dialog to open the CSYS dialog box where you can define the coordinate system. For more information, see CSYS dialog box.To create a coordinate system, select a command from the list.

Constant Physicals page

Stiffness / Structural Damping / Viscous Damping
Defines the stiffness and damping constants. These constants populate the Physical Property Table of the elements element associated data, so that the physical properties are created directly on the element. For more information, see Element-associated data.Note: At least one constant must be different from zero before you can create the connection.
Translation
XYZ	Available for bushing, damper, or spring connections.Represents the translational stiffness or damping of the bushing, damper, or spring along the X-axis, Y-axis, and Z-axis of the defined coordinate system, respectively.
R****Z	Available for bushing connections when Physicals Definition is set to Cylindrical.Represents the translational stiffness or damping of the bushing along the R-axis and Z-axis of the defined cylindrical coordinate system.
Rotation per Radian
XYZ	Available for bushing, damper, or spring connections.Represents the rotational stiffness or damping of the bushing, damper, or spring along the X-axis, Y-axis, and Z-axis of the defined coordinate system, respectively.
R****Z	Available for bushing connections when Physicals Definition is set to Cylindrical.Represents the rotational stiffness or damping of the bushing along the R-axis and Z-axis of the defined cylindrical coordinate system.
Mass
Mass	Available for spring connections.Sets the mass that you want to add to the spring connection.The mass is attached to Target 1 as follows:For Single Point, the mass is attached directly to the selected node.For Set of Points, the mass is attached to each of the first nodes.For Spider, the mass is attached to the center node of the spider.For Local Spider, the mass is attached to the center node of the main spider.When you realize the spring connection, this mass is modeled as a CONM2 element, and it appears in the Simulation Navigator under the 0D Collectors→Concentrated Mass Collectors node.

Dynamic Physicals page

This page appears for the bushing connection.

Dynamic Stiffness / Dynamic Structural Damping / Dynamic Viscous Damping
These options define the frequency-dependent stiffness damping constants by using fields instead of expressions. These constants are optional.
Translation / Rotation per Radian
For each X, Y, and Z field, you can use the following options.For bushing connections, when Physicals Definition is set to Cylindrical, you can additionally use the following options for each R and Z field.
Select Existing Field from List	Opens the Fields dialog box, where you can select a field from a list of existing fields.A field can define a magnitude that varies with independent variables such as frequency, temperature, or time. For more information about fields, see Fields.
Formula Constructor	Opens the Formula Field dialog box, where you can define a formula to construct a field.For more information, see Define a boundary condition using a formula field.
Table Constructor	Opens the Table Field dialog box, where you can define tabular data to construct a field.For more information, see Define a boundary condition using a table field and Define a material property using a table field.
Plot (XY)	Plots the field as an XY graph.For more information, see Plot overview.
Overlay (XY)	Overlays a plot on an existing plot. You can overlay up to 50 plots.For more information, see Overlay plots.
Edit	Opens the Formula Field dialog box or Table Field dialog box, where you can edit the field.
Clone	Opens the Formula Field dialog box or Table Field dialog box, where you can create a copy of a field which you can then edit and use for any other stiffness or damping parameters. It speeds the process of field creation.

Additional magnitude options

Additional magnitude options for boundary conditions
For the physical quantities on the Targets page and Constant Physicals page, you can define the magnitude with a constant value, expression, or field. You can:Type a constant value directly in the box.Type an expression directly in the box. As you begin to type the expression, tooltips provide hints about valid parameter names. If you type an invalid or incomplete expression, the warning icon appears next to the box.Click and select:
Expression	Opens the Expressions dialog box, where you can select an existing expression or create a new one.For more information about expressions, see Expressions.
For more information about other options in the list, see Additional magnitude options.

How do I

Create and edit universal connections

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Universal connections

Bearing universal connection for rotor dynamics (SOL 414)

Using bushing universal connections in rotor dynamics (SOL 414)

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Bearing / Bushing / Damper / Spring Connection dialog box, Simcenter 3D 2021.1 Series

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