01-14-2019 06:44 AM
Hi Alberto,
thank you very much. Now i know how sol601 works. I did the setup you described and defined force to apply at 5seconds. The pressure is applied to reach the maximum at 4 seconds.
If i run the job only with pressure it convergences. But with the setup described below the job begins to not convergence at exactly 5 seconds where the force is added.
Do you have a tip for me?
01-14-2019 07:17 AM - edited 01-14-2019 07:18 AM
@PuddingBaer91, can you share the model?
01-14-2019 07:46 AM
I`ll put my two cents in understanding of SOL 601 and 701. SOL 601,129 can handle with time domain, inertia and other dynamic stuff. The main difference between 601 and 701 is that 701 is explicit solver and 601 is implicit (like all other NX Nastran solvers). SOL 701 used for high-speed and ultra-high-speed problems, like crash test, armor penetration, etc. SOL 601 can work with low, medium and high-speed problems. Explicit solvers require small timestep and must be used with caution, but can solve problems where other fails.
01-14-2019 12:36 PM
Thank you @Karachun for your clarification.
My suggesion to @PuddingBaer91 was focused on "SOL601,106 Advanced Nonlinear Static" solution and not on "SOL601,126 Advanced Nonlinear Transient". I modified my previous posts in order to be clearer.
For this reason I tell that in "SOL601,106 Advanced Nonlinear Static" the time is fictitous: this is a static solution (not a transient solution like instead "SOL601,126 Advanced Nonlinear Transient" or maybe "SOL701").
If I understood well, for this problem a static (non-linear) solution is enought.
01-14-2019 03:32 PM - edited 01-14-2019 03:33 PM
Yes, this is right. Also in SOL 601,106 you can enable "fake dynamics", solver use inertia terms. This can help when you model postbuckling or other cases where stiffness matrix can become singular at some timestep.
Here is screenshot from Femap, maybe in NX setting will be similar.
01-15-2019 05:47 AM
01-15-2019 11:56 AM
Can you post mesh and analysis setting in .dat or .bdf format (I already export model at work and copy to USB flash drive but forgot usb flash itself)?
BTW can you tell what results you want to obtain from this simulation? You already tell how you want to perform simulation, but not tell why (obtain max tangential force when bricks don’t slide or you want to study behavior of whole structure). Answer to this question can give you the right way to solve model.
01-15-2019 03:51 PM - edited 01-16-2019 05:41 AM
Dear @PuddingBaer91, below you can find the file of the model debugged.
Here some notes:
In my case now the simulation take about 600 interations (I think 30-40 min on my laptop, but the computational time depends on hardware resources).
This is caused by the contact of the upper part that is bended under the pressure loading.
Here is the picture of the final step:
I hope that can help you.
Regards,
A
01-16-2019 07:14 AM
Hey Alberto,
THANK YOU VERY MUCH FOR YOUR ENGAGED HELP
I owe you an apology. Because i can't share the real model i have done a quick and dirty representation model with all the errors you explained... sorry
In real model i model only a sector to save ressources. Because of 100 trys to get it working a really made the mistake and didn't divided the force through the sector count. So now it works I also like your tips.
So my problem is now solved
Thank you very much Alberto
02-25-2019 05:58 AM