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Long simulations

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Posts: 1
Topic starter
(@bjohnterry)
Barista
Joined: 4 years ago

Is it possible to run a 20 seconds simulation in LSDYNA?

Eg: A robotic device moving on a surface and gripping a box. The total duration of this process is about 20s. I would like to simulate this entire process in DYNA.

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tNine
Posts: 11
(@tnine)
Paid Intern
Joined: 4 years ago

This sounds more like MBD simulation to me. I would go with ADAMS for this kind of simulation.

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Negative Volume
Posts: 647
Admin
(@negativevolume)
CEO
Joined: 6 years ago

@bjohnterry You'd need to run an implicit simulation and even then a 20 sec simulation may encounter some issues. What exactly are you trying to study and why use LS-Dyna for this? 

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Posts: 21
 ANA
(@ana)
Paid Intern
Joined: 4 years ago

To speed up the simulations in ANSYS LS-DYNA (student version), what is your suggestion? Currently, a simple case takes almost a few hours (on a pc with RAM 32, core i7 CPU 2.6), which makes it frustrating to go for a more detailed model. It is mentioned this student version will run at most on four (4) cores. Therefore, what is your suggestion? How about a server, CCDB account, AWS, or any other alternative?

 

Thanks,

 

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2 Replies
Negative Volume
Admin
(@negativevolume)
Joined: 6 years ago

CEO
Posts: 647

@ana Unfortunately, your only option with the student version is use the SMP version of LS-Dyna to run on a local machine. SMP stands for Shared Memory Parallel and means that LS-Dyna will use up to 8 cores to run the simulation, but all 8 cores have to be on a single machine. If you want to run the simulation across a cluster of computers you would need to use the MPP (Message Passing Parallel) version. This allows you to use hundreds of cores across different machines. But this is not included with the free student version. 

So you would need a cluster accessible through your university and a paid license of ls-dyna to install. Alternatively, There are services that you need to pay to use which allow you to run simulations through them on their hardware. I don't know many right now though. 

If you want to use the student license, you can remesh your model to eliminate very small elements in order to increase your timestep, change material properties to more computationally efficient ones, introduce more rigid parts where possible, or utilize mass scaling to increase your timestep. 

https://www.dynasupport.com/faq/general/i-have-very-long-run-times.-what-can-i-do

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 ANA
(@ana)
Joined: 4 years ago

Paid Intern
Posts: 21

@negativevolume As always, your help is appreciated!

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