Learning Forum

[douk.van.werven]

Hi, I want to use LS-Dyna (workbench) for droptest simulations of appliances. I have completed the followoing course that contained a droptest tutorial/ case study. This was very helpfull in learing about how to do a droptest in LS-Dyna workbench.

https://learninghub.ansys.com/learn/courses/683/ansys-workbench-ls-dyna/lessons/4092/ansys-workbench-ls-dyna

I still have some challenges with performing my droptests and would like to know if there is more content focussed on setting up/ improving droptest simulation in LS-Dyna. I have mainly issues with body interactions/ bodies going trough each other.

Are there more tutorials/ case studies for workbrench LS-Dyna droptest available?

Kind regards,

Douk

[Dennis Chen]

 

the key suggestion I can make is you really don’t want to just rely on workbench’s defaults such as those body interactions which turn into a 0,0,5 single surface contact.   I would rely on workbench dyna to only produce the input file and you want to judge the input file written from workbench to judge how well the model’s set up.   I would also suggest using LSPP to check model before solving and postprocess afterwards.    What you do not want to do is click keys in workbench and click solve there.   Dyna isn’t ansys mechanical who’s much more mature in incorporating APDL features without running into problems (it’s probably decades behind). 

here’s a video that I hope will help you, happy holiday! 

https://www.youtube.com/watch?v=dybvi8VsZvQ

 

 

 

 

 

 

[douk.van.werven]

Hi Dennis, thanks much for your input. I get your point that LS-Dyna is more powerfull when not used from Ansys workbench. I must say the intergration is not great yet, but since I have good experience with Ansys mechanical, using LS-Dyna is now availble to me with a manageble amount of training. Hopefully the integration will soon be better and more complete, because I can work well with the mechanical interface. Switching to LSPP seems not like a quick and easy step over I imagine?

At the moment I am using indeed body interactions for bodies that can colide with each other. I use frictional with following settings:

Problem is that parts move trough each other like this. See issue below where hook goes trough other part. Could this happen because mesh has initital penetraions between the parts? 

 

 Any tips to improve are helpfull! And nice holidays to you!

[Armin]

Hi Douk,

If you have already completed the Workbench LS-DYNA Getting Started course on the Ansys Learning Hub, there is another course focused on the drop tests using Workbench LS-DYNA that you may find helpful: Drop Test Simulation Using Ansys Workbench LS-DYNA - Ansys Learning Hub

As a general suggestion, besides avoiding initial penetration that you mentioned, try to reduce the use of Body Interactions and instead use contact pairs scoped to specific surfaces of the parts if you know how the interactions would occur. This will also reduce computational time.