Learning Forum

[Rajesh B]

I am trying to run dyna model, the run initates and run for 3ms and it stops. Not showing any error messages in the d3hsp or message files.

[Reno Genest]

Hello Rajesh,

Which LS-DYNA solver are you using? Are you running SMP or MPP? If MPP, a meaningful error message may be written in one of the mesXXXX files. Please check all mesXXXX files.

We have seen this problem before where the solver hangs without an error message and the calculation does not move forward. In this case, I would try running with another solver revision. You can download different revisions here:

https://lsdyna.ansys.com/downloader-filter/

username: user

password: computer

You will find the latest  release (R14) here:

SMP:

https://ftp.lstc.com/user/ls-dyna/R14.0.0/

MPP:

https://ftp.lstc.com/user/mpp-dyna/R14.0.0/

 

Let me know how it goes.

 

Reno.

[Rajesh B]

We are using MPP and solver 10.2, this is full vehicle crash model. Currently we are using only version 10.2, we have issue and difference in result if we use the higher version of Dyna.

[Reno Genest]

Hello Rajesh,

Were you able to find an error message on one of the mesXXXX files?

You ran the model on how many cores? Can you try a different core count? 

Have you tried running double precision?

Also, which MPI are you using (Intel MPI? Platform MPI?). Have you tried with a different MPI? 

You can use the *CONTROL_MPP_IO_LSTC_REDUCE keyword to get the same results with different MPI. Here is what the user manual says:

"For numerical consistency, LSTC_REDUCE was developed to ensure a deterministic
summation order. This keyword gives identical results while using
the same decomposition and core counts but different MPI algorithms."

 

You can download the LS-DYNA manuals here:

https://lsdyna.ansys.com/manuals/

 

Let me know how it goes.

 

Reno.

[Rajesh B]

We have no error message in any of the output files. This is the first time we are facing this issue. 

We used *CONTROL MPP IO LSTC REDUCE also, still not running.

I will try to  run in double precision.

Thanks for the reply.

[Reno Genest]

Hello Rajesh,

Ok, also try with other MPIs and a different core count.

If you are not able to find a solution, I think you will have to submit a service request on the Ansys customer portal:

support.ansys.com

Ansys employees are not allowed to updload and download files on the Ansys forum. With an SR, we are able to do a Teams meeting and have a look. Also, we can get your model and have it looked at by a developer. With no error message, it is difficult to troubleshoot.

Let me know how it goes.

 

Reno.

 

[Rajesh B]

Sure, Thank you