Engineering Solutions

Bodies panel

Bodies panel

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Bodies panel

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Use the Bodies panel to create, review and update group entities. The Bodies panel is only available when the OptiStruct user profile is loaded. These group entities directly correspond to OptiStruct body definitions; rigid body (type = PRBODY), flexible body (type = PFBODY) and ground body (type = GROUND).

 

Subpanels and Inputs


The Bodies panel contains the following subpanels and command buttons:

hmtoggle_arrow1Create

Use the Create subpanel to create a new body definition for the OptiStruct MBD solution sequence.

 

Panel Inputs

Input

Action

body

Type a name for the new body in this field, or select an existing body by double-clicking body = and selecting the desired body.

type

Select a type from the pop-up list.  There are three body types to choose from:

PRBODY: a rigid body
PFBODY: a flexible body
GROUND: a ground body

Please refer to OptiStruct documentation for more details on the body types.

body color

Choose a color for the new body.

properties: props

To include elements in the body being created, use the props selector to pick properties referenced by elements.

rigids: elems

Use the elems selector to choose rigid (RBAR, RROD, RBE2, RBE3), or mass (CONM2) elements for inclusion in the new body.

free nodes: nodes

Use the nodes selector to pick additional free nodes for inclusion in the body being created.

CMS Method

This selector only appears when PFBODY is the chosen type.  Use it to choose the type of Component Mode Synthesis to perform while creating of the flexible body.

Click the toggle to switch between the Craig-Bampton and Craig-Chang methods.

frequency upper bound

This selector only appears when PFBODY is the chosen type.  A default upper boundary for the frequency is determined automatically.  To use a specific upper boundary instead, change the toggle to ub_freq = and type in the desired upper bound.

You only need to define frequency upper bound or number of modes (see next entry), not both.

number of modes

This selector only appears when PFBODY is the chosen type.  A default number of modes is determined automatically.  To use a specific number instead, change the toggle to nmodes = and type in the desired number of modes.

You only need to define frequency upper bound (see previous entry) or number of modes, not both.

 

hmtoggle_arrow1Update

Use the Update subpanel to update a body definition for the OptiStruct Multi-Body Dynamics solution sequence.

 

Panel Inputs

Input

Action

body

Type a name for the new body in this field, or select an existing body by double-clicking body = and selecting the desired body.

type

Select a type from the pop-up list.  There are three body types to choose from:

PRBODY: a rigid body
PFBODY: a flexible body
GROUND: a ground body

Please refer to OptiStruct documentation for more details on the body types.

body color

Choose a color for the new body.

properties: props

To include elements in the body being created, use the props selector to pick properties referenced by elements.

rigids: elems

Use the elems selector to choose rigid (RBAR, RROD, RBE2, RBE3), or mass (CONM2) elements for inclusion in the new body.

free nodes: nodes

Use the nodes selector to pick additional free nodes for inclusion in the body being created.

CMS Method

This selector only appears when PFBODY is the chosen type.  Use it to choose the type of Component Mode Synthesis to perform while creating of the flexible body.

Click the toggle to switch between the Craig-Bampton and Craig-Chang methods.

frequency upper bound

This selector only appears when PFBODY is the chosen type.  A default upper boundary for the frequency is determined automatically.  To use a specific upper boundary instead, change the toggle to ub_freq = and type in the desired upper bound.

You only need to define frequency upper bound or number of modes (see next entry), not both.

number of modes

This selector only appears when PFBODY is the chosen type.  A default number of modes is determined automatically.  To use a specific number instead, change the toggle to nmodes = and type in the desired number of modes.

You only need to define frequency upper bound (see previous entry) or number of modes, not both.

 

hmtoggle_arrow1Parameters

Use the Parameters subpanel to add or update additional but nonessential information to a body definition for the OptiStruct Multi-Body Dynamics solution sequence.

 

Panel Inputs

Input

Action

body

Type a name for the new body in this field, or select an existing body by double-clicking body = and selecting the desired body.

Once you select a body, the rest of the subpanel are populated with the appropriate entry controls.

flex nodes

Use the flex nodes selector to specify one or more nodes.

2.Use the dof checkboxes to.
3.Click add.

 

You can also remove interface nodes from the body definition:

1.Use the flex nodes selector to specify one or more nodes.
2.Click remove.  This deselects all degrees of freedom.

dof1-dof6

Specify the appropriate degrees of freedom for the selected nodes.

do not determine interface nodes automatically

This checkbox prevents automatic determination of flexible body interface nodes, so that you can specify them yourself.

damping

You can define a critical damping ratio in place of default damping for flexible bodies by changing the toggle to dval =, and typing in the desired ratio.

mass

The selected body’s total mass. This overrides computations based on material and property information that would otherwise occur.

lxx, lyy, lzz, lxy, lxz, lyz

Explicitly define the selected body’s values. This overrides computation based on material and property information that would otherwise occur.

global system/ local system

Select the coordinate system to which the defined moments of inertia are related.

COG

Choose the location of the center of gravity by selecting a grid point in the display, or double-click COG to type in the coordinates.

 

hmtoggle_arrow1Command Buttons

The following action buttons appear throughout the subpanels:

Button

Action

create

Creates the new body using the specified settings.

review

Click review after selecting the body to enter a body review mode. In this mode the body’s constituent entities display in red while selected flex-nodes of a flexible body display in blue.  The remaining model is drawn in gray.

This review mode is a temporary graphics mode; you can exit out of the "body review mode" by clicking review again or leaving the panel.  While in "body review mode", use review opts to customize the graphical review of the bodies:

force transparency view: When turned on, displays the entities that are not part of the body in a transparent view so that the entities in the body can be easily viewed.
Gray color view/element color view: When gray color view is selected, the entities that are not part of the body are all displayed in a gray color, improving the highlighting of the master and slave entities. When element color is selected, the entities that are not part of the body are displayed in their original element color.
display entities: Turn the display of body entities on/off while in the review mode.

card image

See the card image for the selected body.

update

Update the selected body definition with your new settings.

update color

Update only the body color. All other settings remain unchanged, even if you changed them in this panel.

return

Exit the panel.

 

 

See Also:

Alphabetical List of Panels