Learning Forum

[jerome chassin]

Hello all,

I am creating an API in order to automate a set of simulations. (Modal, Random vibration, Transient shocks, Statics, in total more than 25 simulations).

Some of them are using bushing elements, and other remote displacements but not both in the same time. These are sharing the same surface/Edge as boundary conditions.

For now, I only activate/deactivate the remote displacements/Bushing connections corresponding to the adequate simulations but I would like to avoid this.

My solution:

1/add an APDL command in the bushing element giving it an ID:

With the following AD: Damp_1 = _JID

And so on, with all bushing elements ( this can be scripted easily)

2/Add an APDL command in the modal analysis to suppress Bushing connection using "esel" command for each bushing:

Note: we can considere here that remote displacement are blocked in the all direction

The solution dont seems to take into consideration the remote displacements--> the 6 first mode=0Hz.

The command seems to work for static.

Any Idea where I am missing the point?

--> I guess that bushing elements "overide" the remote displacement in the solver... 

 

Thank you very much for your help.

[Chandra Sekaran]

can you verify that remote displacement is active? May be issue DLIST command to check if the remote displacement is taking effect (or look at ds.dat to make sure the remote displacement is being applied).

[jerome chassin]

 

 

I am not really use to APDL Command, and I am kind of lost here. How do you sugere using DLIST? (With the ACT console?)

I marked a remote displacement as “TestBC1” to find it easier in the ds.dat.

Here what I found, in both file ds.dat we have the remote displacement declared. With the APDL script and bushing activated it is also declared, while it is not when we manually suppress the bushings ( everything is normal here). With the script I am suppressing bushing when the APDL Command is called by the solver.

 

I also checked the "spider" BC should be applied.