MotionView can write input decks for the Abaqus solver. Users can:

The results of the Abaqus solver can be post processed in HyperView.

Here is the flow of flexible body creation and integration:

Integrating Abaqus substructure or FE model in MotionView

Exercise

In the first step of the exercise, you will be creating an Abaqus substructure. The second step involves the replacement of the rigid lower control arm with the Abaqus substructure. In the third step you will run the solver, and in last step you will post process the results.

Copy the folder abaqus, located in the mbd_modeling\externalcodes folder, to your <working directory>.

Step 1: Creating the Flexible Body Substructure.

First, you will need to create the flexible body.  This stage must be completed in Abaqus, independent of MotionView.

It is assumed that you are familiar with flexible multi-body dynamics in Abaqus. Here is a brief overview of the steps you would need to do in Abaqus to generate a substructure:

*NODE...

*ELEMENT...

*MATERIAL...

*STEP

*FREQUENCY, EIGENSOL=LANCZOS

20

*BOUNDARY

RETAINED_NODES, 1, 6

*END STEP

*STEP

*SUBSTRUCTURE GENERATE

TYPE=z2, LIBRAYR=carm_right, MASS MATRIX=YES, OVERWRITE, RECOVERY MATRIX=YES

*RETAINED NODAL DOFS, SORTED=NO

RETAINED_NODESET,1,6

*RETAINED EIGENMODES, GENERATE

1,20,1

*END STEP

This is just a sample deck.  For detailed syntax you may have to look up Abaqus documentation.

The intermediate files (*.stt, *.mdl, *.prt) created by Abaqus during the substructure generation analysis are required for reference during the MBD system analysis. You will need to generate these files in Abaqus.  The result files (*.mrf, *.odb) which are needed for the post-processing step of this tutorial are provided.

Once the substructure is generated you should be ready to integrate it in your MBD model.

Step 2: Integrating a Flexible Body into the MBD System.

Once you complete the substructure generation step in Abaqus, you should have the <substructure-name>.sup file. This .sup along with the original <substructure-name>.inp file will be used to integrate your flexible body into MotionView.

Notice that the graphics of the rigid body lower control arm vanishes.

Now you would need to specify a particular INP file that was used to create the flexible body.

Properties tab

Notice that the Inp file field is automatically populated by MotionView.

If the INP file is located in the same directory as the H3D graphic file, the Inp file field would be populated automatically.  Otherwise, one also has the option of selecting the INP file from its respective location.

The Nodes dialog is displayed.

Nodes dialog

You can attach joints to the flexible body only at the interface nodes.  These attachment nodes are created during your substructure generation analysis in Abaqus.  Creating more attachment points increases the actual number of modes calculated, and may increase the CPU time.

Your model should look like the image below:

Step 3: Running MBD Systems in ABAQUS.

The flexible bodies are now fully integrated in your model. Now you will set up the ABAQUS solver run.

MotionView writes out the INP file for the whole MBD system. It is important that this INP deck should contain the substructure path references for the model to run successfully in Abaqus.  The way to include these is via Templates in MotionView.  Templex templates can be used to export syntax directly to the solver input deck, including parametric substitution if required.

The remaining text of the template is written according to the position specified. In this case there are two substructure paths included for the two flexible bodies. You will need to add or delete such paths depending on the number of flexible bodies integrated in your model.

{MODEL.sys_frnt_susp.b_lca.l.idstring} is the parameterized path to grab the element ID number assigned to the left arm substructure.

Now your model is complete and ready to run in ABAQUS solver.

Step 4: Post-processing Abaqus Results.

You will now load the results of the Abaqus run in the Animation window.

The carm_left.odb and carm_right.odb files needed in this step will be generated once the model successfully runs in Abaqus.

Notice that the substructures are overlayed on your model.