Reply To: LS Dyna full deck restart

[Reno Genest]

Hello Ajay,

Do you have the original input file (first_Impact.k) and the restart file (2nd impact; restart.k) in the same folder? You should have results of the first impact (include dynamic relaxation state at time=0) in the d3plot. When you restart, LS-DYNA will continue the d3plot file series as d3plotaa and keep adding results. It should look like this:

So, when you open the d3plot file, you will get results from the first and second impacts.

I recommend doing some tests with a simple cube model. This way you will be able to run quickly and make changes as needed.

Here is the full restart procedure from our knowledge database:

"Changes of a general nature can be made in a full restart, including addition of parts, loads, and contacts.  

 Sample execution line  

SMP:  lsdyna i=fulldeck.k  r=d3dump01

MPP:  lsdyna i=fulldeck.k  n=d3full01

where fulldeck.k is a complete keyword input deck for the model you want to use moving forward in time.  

Copyright © 2003-2012 by LIVERMORE  SOFTWARE  TECHNOLOGY  CORPORATION                        

Full Restart (cont’d)

 Guidelines for fulldeck.k 

 Include keyword input for anything that is to be retained from the original run… (*PART, *SECTION, *MAT, *CONTACT, *LOAD, etc.).  Normally, you would just copy the original input deck and strip out anything you don’t want to retain.  

 Also include keyword input for new parts, materials, contacts, loads, etc.

 Include all relevant *DATABASE and *CONTROL commands.

 Include the command *STRESS_INITIALIZATION.

 Signals to LS-DYNA this is a full retart and that stress, strain, displacement, etc. are to be initialized for specified, pre-existing parts.

 Do not use *INITIAL_VELOCITY for nodes carried over from previous run.  Use *CHANGE_VELOCITY_option  to modify velocities of such nodes.

 Preexisting contacts that are to be retained should include the _ID option so that the contact ID numbers in the original input deck match those in the full restart input deck. 

 Regarding output from a full restart:

 Binary output (d3plot) from a full restart will blend seamlessly with previous output.  

 ASCII output (glstat, matsum, etc.) from a full restart appends to pre-existing ASCII output only if *CONTROL_OUTPUT with IASCII=1 in included in the full restart deck.

 Without this command, ASCII output from full restart overwrites pre-existing ASCII output.

 Lastly, there may be a suitable alternative to using a full restart.  

 For example, a “dynain” file can be written at the conclusion of the original run by including the command *INTERFACE_SPRINGBACK_LSDYNA in the original input deck.   This dynain file can be included in a subsequent keyword input deck to initialize nodal coordinates and element history variables (stress, strain, etc). "

https://ftp.lstc.com/anonymous/outgoing/support/FAQ_docs/restart.pdf

https://ftp.lstc.com/anonymous/outgoing/support/FAQ/restart

 

Let me know how it goes.

Reno.