Adams Basic Package > Adams View > Adams View > Dialog box - F1 help > A - D > Create a Flexible Body

Create a Flexible Body

Ribbon menu → Bodies Tab → Flexible Bodies container → Adams Flex: Create a Flexible Body

(Classic) Build → Flexible Bodies → Adams Flex

Imports a flexible body into Adams Flex. You specify a Modal Neutral File (MNF) or MD DB file (.MASTER) or, for a nonlinear flexible body, a Bulk Data File (BDF) and Adams View creates the necessary Adams View geometry for displaying the flexible body. It also creates a mesh on the flexible body representing the flexible body nodes.

By default, Adams Flex places the flexible body so the flexible body’s local body reference frame (LBRF) is at the origin of the global coordinate system. The LBRF corresponds to the origin of the finite element (FE) environment in which the body was originally modeled. You can also set the location and orientation as you import the body or after it is imported as you do any element in Adams View.

For the option:	Do the following:
Flexible Body Name	Enter the name you want assigned to the flexible body.
Modal Neutral File Name or MD DB File Name or, for a nonlinear flexible body, a Bulk Data File (BDF)	Select the appropriate option and enter the name of the MNF, MD DB or BDF file. Tips on Entering File Names in Text Boxes. Note: When you use the Browse command to search for a file, it places the absolute path to the file in the text box. When you save the database or a command file, Adams View uses the absolute path in the saved file. If you are sharing the database or command file with other users, you may want to edit the path that the Browse command places in the text box so it is a relative path or remove it altogether if the MNF/MD DB file is in the current working directory.
If MNF or MD DB options is selected the following options displayed:
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.
Import All	This option can be used as an alternative to specifying an index. Using this option will import all flexible bodies in the specified MD DB at once. All the created bodies will have a default location and orientation as (0,0,0).
Damping Ratio	Do one of the following: ■Leave use default selected to accept the default nonzero damping as follows: ■1% damping for all modes with frequency lower than 100. ■10% damping for modes with frequency in the 100-1000 range. ■100% critical damping for modes with frequency above 1000. ■Clear the selection of use default, and then enter: ■Scalar damping ratio that you want applied to all modes. ■Adams run-time function expressions to create complex damping phenomena in your flexible body. In addition, function expressions, such as FXFREQ and FXMODE, allow you to apply different levels of damping to individual modes. To get help entering a function expression, right-click the Damping text box, and then select Expression Builder to display the Adams View Function Builder. For information on using the Function Builder, see Adams View Function Builder online help. Shortcut to Function Builder: Click the More button . Learn more about Specifying Damping.
Generalized Damping	Select one: ■Off - Disables the generalized damping. ■Full - Enables the complete generalized damping matrix, including the effects of a resultant damping force. ■Internal Only - Only enables the portion of the generalized damping matrix corresponding to the modal coordinates (that is, ignore the resultant damping force).
If BDF option is selected the following options displayed:
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
Location	Enter x, y, z coordinate defining the flexible body's location in the default coordinate system.
Orientation	Specify either of these three orientation methods: ■Orientation ■Along Axis Orientation ■In Plane Oriention
Relative to	You can: ■Specify the orientation coordinates. ■Leave blank to use the default coordinate system.
Test Modal Translate	Select to display the Test Modal dialog box to translate either: ■MSC.Nastran output data into a MNF. You generate the output data by first running MSC.Nastran with the AdamsMNF Case Control command or a special DMAP alter. ■Universal file into a MNF that you can use to create a flexible body with a constant coupling inertia invariant formulation.
MNF XForm	Select to display the XForm dialog box to transform the flexible body. This dialog box uses the MNFXFORM command from the Adams Flex Toolkit command line. See Working with the Adams Flex Toolkit Command Line for more information.
If you check the More option following parameters will appear
Dynamic Limit	Specify the threshold frequency for quasi-static modes. Any mode with frequency higher than this value will be treated as quasi-static.
Stability Factor	Specify the amount of damping needed to add to the quasi-static modes. This is required to stabilize the simulation.

Notes:

Adams MNF Import (> ~10MB) May Cause SUSE System to Hang.

In Adams importing .mnf files greater then approximately 10MB in size may cause the machine to hang/freeze on SUSE Linux operating systems. The root cause is a configuration setting of the NVidia driver typical for normal users. The workaround is to change the NVidia configuration file like so:

■Open the 50-nvidia.conf which is located at /etc/modprobe.d

■Change permission from 0660 to 0666.

■Reboot the machine

Note:

With version 2015 or before, Adams MD DB import only supported Nastran i4 database files. In version 2015.1 or later Adams MD DB supports only i8 files. Support for i8 begun with MSC Nastran version 2016.