I am currently working on a project where I would like to be able to change which node is the master node for my flexible body. Is there a way to do this in ADAMS?
An MNF file is a binary file that can be accessed for certain modifications through the Adams Flex toolkit. However, modifying the RBE elements is not one of the aspects that can be modified.
For that, you would need to modify the original Nastran (FEA) input deck and re-run the MNF-generating solution.
Don't know what you have in mind, but maybe creating markers in ADAMS with the node_id = <list> and "preserve_location" option could do the job ?
In a nutshell: You can create something like RBE3 elements in ADAMS by creating a marker outside the mesh and giving it a list of nodes with node_id = 1,2,3,4,..
preserve_location = true prevents ADAMS from shifting the newly created marker to the nearest existing node.
Thank you for your answers. My problem is that I don't have a Nastran license. I use ABAQUS for creating the .mnf and when I create the flexible body in ADAMS all the nodes are treated as master nodes. I was hoping there was an easy way in ADAMS to fix this.
I am on thin ice :), but i think that you can do mnf without interface nodes (master node???) and then use @Martin Kieltsch propose to create spider web in adams.
Try search help in adams: Configuration 3: Attached to Multiple Nodes
The help is little bit outdated (fortran is not default solver for some versions of Adams)
As indicated by Martin, you can make use of the marker command to attach it to multiple FEA nodes on a flexible body to create your rigid body element definition in Adams. This is provided that you know the node numbers well.
Please let me know if there are any questions in implementing this approach.
As you know a mnf is a "simplification" of your original FE model that is based on the Eigen solution. All modes are "overlayed" to create a form that matches exactly at the dedicated interface nodes which means the chosen nodes and the solution are dependent from each other.
For all other nodes in between the solution is kind of "not exact". As a consequence it wouldn't be very smart to create a mnf without interface nodes and just use any arbitrary nodes in between.
BTW: For the same reason the stress recovery from mnf's is not as exact as for example a Nastran SOL400 run.
