Swap a rigid body for another flexible body
Ribbon menu → Bodies tab →Flexible Bodies container → Rigid to Flex 
or
(Classic) Build → Flexible Bodies → Rigid to Flex
(Template-based products, Standard Interface: Adjust → General Part → Rigid to Flex)
(Template-based products, Standard Interface: Adjust → General Part → Rigid to Flex)
Lets you substitute a rigid body for an Adams Flex flexible body. The name of the replacement flexible body is the name of the existing body with _flex appended to it.
Learn more about Replacing Existing Bodies with Flexible Bodies.
To substitute a rigid body for a flexible body, you use the following tabs:
Alignment
For the option: | Do the following: |
|---|---|
Current Part | Enter the rigid body to be replaced. For template-based products: Enter the general part to be replaced. If the general part has a symmetric brother (counterpart), both the left/right general parts will be set to asymmetric, and only the general part specified will be made flexible. |
Flex Body/ MNF File/ MD DB File/ BDF | Select either: ■Flex Body, and then select a flexible body that already exists. ■MNF File, and then select the name of the MNF to import. ■MD DB File, and then select the name of the MD DB to import. The index parameter applies only to MD DBs. The appropriate index of the body in the specified DB file, is input here. If not specified, it is assumed that the value is 1. ■Bulk Data File (BDF) for a nonlinear flexible body. |
Index | The parameter applies only, when the user is creating a flexible body out of the MD DB. The parameter specifies the index of the flexible body in the specified MD DB. The parameter is optional. If not specified, it is assumed to have the value 1. Note: The user can wish to view all the flexible bodies in the MD DB, using the “…” button provided beside the index. The desired flexible body can be selected by double-clicking on the displayed list. |
Load | The load button needs to be/can be used only when the user specifies a MD DB option, to create the replacement flexible body from. Pressing the load button, after specifying a valid MD DB file (and index if specified), loads the appropriate flexible body from the MD DB. For the flex-body and MNF option, the load button stays disabled and cannot be used. |
Flex Body Positioning | |
Node ID Method | Select this method to automatically align the flexible body based on the locations of three Markers with identical Node ID specified in both the original and swapped bodies. Three markers that are not collinear are selected for the swap, and the swap is performed automatically if the triangle formed by the three markers of both bodies are identical. If no Markers with Node ID specified can be found that meet this criteria, an error message is issued and the swap is aborted. |
Align Flex Body CM with CM of Current Part | Select to align the flexible body by comparing the center of mass and inertia tensor of the two bodies. The flexible body is: ■Positioned such that its center of mass (CM) is coincident with the rigid body CM. ■Oriented such that its principal inertia directions are coincident with the part's principal inertia directions. If the inertia properties of the two bodies are similar, this method closely aligns the flexible body with the rigid body. If the bodies are symmetric about a plane, this method may rotate the flexible body 180° from the rigid body. In this case, you can use the Flip about buttons to rotate the flexible body 180° back into position. |
Launch Precision Move Panel | Displays the Precision Move dialog box, which lets you move objects either by increments or to precise coordinates. |
3 Point Method | Select to specify three point pairs to define the location and orientation of the flexible body. A point pair consists of a point on the rigid body and a point on the flexible body. The three points on each body must uniquely define a plane. The first point pair defines the location of the flexible body and the second and third points define the orientation. The flexible body is positioned by making the first point pair coincident. It is then oriented by making points 2 and 3 on the flexible body reside in the plane defined by points 2 and 3 on the rigid body. |
Flip about | Only available if you used Align Flex Body CM with CM of Current Part. Select either of the following to rotate the flexible about the corresponding axis: ■X axis - Rotate flexible body 180° about its largest principal inertia direction ■Y axis - Rotate flexible body 180° about its second largest principal inertia direction ■Z axis - Rotate flexible body 180° about its smallest principal inertia direction |
View Parts Only | Select to display only the rigid body and the replacement flexible body. |
View Topology | Select to display a representation of the rigid body and its connections to other parts. Learn more about Graphically Viewing Model Topology. |
Copy original part | Leave a copy of the original rigid body in the modeling database. This is helpful if you want to reactivate the rigid body. For template-based products: The original part is always copied. |
Connections
For the option: | Do the following: |
|---|---|
Update table | Select to update the Marker and Node table with the changes you've made. |
Reset table | Select to reset the Marker and Node table to the original connections found. |
Node Finder | Select to display the Node Finder Dialog Box and search for nodes. |
Display only active markers/connections | Select to display only those markers and connections that are currently active. Inactive markers/connections will not be displayed in the table. |
Align All Via | Select this button to align all the Align column choices as per the option selected. |
Move Marker to Node | Select to move the marker in the selected row of the Marker and Node table to the location of the specified node. |
Preserve Marker Expression | Select to maintain the parameterization of the marker in the selected row of the Marker and Node table. The parameterization would be specified through Adams View expressions. This will keep the marker at its parameterized position. |
Preserve Marker Location | Select to maintain the location of the marker in the selected row of the Marker and Node table. If a marker is not coincident with the attachment node, Adams Flex preserves the offset. This is helpful if you have defined a joint location on the marker. It keeps the joint from breaking. Note: Adams Solver (FORTRAN) does not support markers offset from their attachment nodes. Therefore, Adams Flex (FORTRAN) automatically introduces a massless link between the marker and the flexible body. Learn more. |
Move Node to Marker | Select to move the node in the selected row of the Marker and Node table to the location of the marker location. The node must be an attachment node. This option will invoke Adams Flex in the background and generate a new MNF with the node(s)' positioned edited. This MNF will then be used for the swap. Note that the modal content of the MNF is not changed by this action. The modal response of the flex body may be approximate, depending on how much the attachment node has been moved from its original location. Moving a node to a marker location removes the need for a rigid offset to be maintained by Adams Flex between node and marker location during the simulation. Comparing this option to preserving the marker location: both result in an approximate solution. If the offset is significantly far from zero, the 'move node' option may be better since no artificial moments are introduced. If offset is close to zero, the artificial moment may be negligible. |
Number of digits | Enter the number of digits displayed to the right of the decimal point in the Marker and Node table. |
Sort By | Select how to sort the Marker and Node table based on the headings of the columns. For example, you can sort the table by the marker that is the most distant from its selected node. ■Marker - Sort alphabetically by marker name. ■Connections - Sort by those markers with connections. ■Node ID - Sort by the ID of the node. ■Interface - Sort by those nodes that are interface nodes. ■Distance - Sort by those markers the most distant from the selected node. |
Marker and Node Table | Displays the markers on the existing body and the node to which the marker will be transferred on the replacement flexible body. ■Marker - All the markers on the rigid body that will be transferred to the flexible body. ■Connections - All the forces and joints on the rigid body that use the marker for their definitions. These joints and forces will be transferred to the flexible body. ■Marker Location - Marker's current location. ■Node ID - The attachment node chosen for the marker when it is transferred to the flexible body. When Adams Flex initially creates the table, it chooses the closest node. You can change the chosen node using the node id cell itself. ■Interface - An asterisk (*) in this column indicates that the chosen attachment node is an interface node. ■Relative Location - The x,y,z coordinates of the chosen attachment node relative to the marker's current position, resolved in the marker's coordinate system. A perfect match is 0. ■Distance - The magnitude of the relative location vector. |
■Align column - Indicates how Adams Flex will position the marker. The three options are: ■Move Mar - When Adams Flex transfers the marker to the flexible body, it will move it to the chosen attachment node. How far the marker will be moved is given in the Distance column. ■Mar Loc - The current location of the marker will be preserved. If the marker's position was defined by an Adams View expression, the parameterization will be lost. ■Mar Expr - If the marker's position is defined by an Adams View expression, the parameterization will be preserved. Otherwise, the marker's current position will be preserved. This is helpful if you have defined a joint location using the marker. It keeps the joint from breaking. ■Move Node - When Adams Flex transfers the node to the marker location, it will move it to the chosen marker location. How far the node will be moved is given in the Distance column. The node must be an attachment node. This option will invoke Adams Flex in the background and generate a new MNF with the node(s)' positioned edited. This MNF will then be used for the swap. Note that the modal content of the MNF is not changed by this action. The modal response of the flex body may be approximate, depending on how much the attachment node has been moved from its original location. Moving a node to a marker location removes the need for a rigid offset to be maintained by Adams Flex between node and marker location during the simulation. Comparing this option to preserving the marker location: both result in an approximate solution. If the offset is significantly far from zero, the 'move node' option may be better since no artificial moments are introduced. If offset is close to zero, the artificial moment may be negligible. You use the Move Marker to node, Preserve Marker location, Preserve Marker expression, and Move Node to Marker options to set the Align column value. | |
Mass, Force, Length, Time | If the BDF does not specify its modeling units, they must be specified here. If the BDF does specify its modeling units, they will be shown here. If the BDF units differ from those of the Adams model, Adams View will scale the geometry and mass properties appropriately in session; however, it does not edit the values within the BDF to reflect the Adams model units. |