Learning Forum

[novak1]

Hello.

I am simulating a 3 point bend test of a 4 layer composite material using implicit solver in workbench LS-DYNA.

1. I would like to extract the reaction force from the loading pin to compare the Force by Time graph with the experimental one.
I have seen a previous version from 2014 with an option under LSDYNA Post, but my Ansys 2020 R1 does not contain it.

2. Is there a keyword option to plot a graph from workbench LS-DYNA?

 

Thank you.

Best regards
Lin Novak

[Sandeep Medikonda]

Hi,

It is still possible to do this in 2020R1, just right click on solution information and add it:

[novak1]

 Hi,

thank you for the answer!

I have attached added the Force Reaction as you suggested. Unfortunately the result is a flat line, with no real input information. I have read through the link you attached and at the bottom it mentions  "The Force Reaction trackers are only available for an Explicit Dynamics analysis". If I understand it correctly, the information can only be read with an explicit solver. Am I not getting the force information because I am using the implicit solver inside LS-DYNA?

1.I have tried different Location methods and also checked the Contact/External force but no positive results were gained.
2. I have changed the solver to explicit, to check if the Force reaction can be gained, but by doing so, I had to change my mesh, and the speed of the loading pin to make the simulation finish in a timely manner.
3. Do you have any suggestions how I am able to simulate a 3 point bending test, with a loading pin velocity of 2mm/s, a visible delamination+erosion and an option to read the Reaction Force on the loading pin? The simulation end time is around 13 seconds, which makes an explicit solver a week long simulation option.

Thank you for your time!
Best,
Lin Novak

[Sandeep Medikonda]

The output files shouldn't depend on the solver....typically, rcforc and spcforc should automatically be generated and contain information on contact forces and reaction forces respectively. You can check if these files are being generated in the solver files directory. If you are using the distributed solve (or MPP) they should be in the binary output (binout000) which you can review in LSPP. Try running your model by turning off distributed solve (i.e., run in SMP).

https://ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v201/en/exd_ag/exd_ag_lsdyna_ascii_files.html

and explicitly request the output by adjusting the frequency

Also, have you tried External Force, which should record the forces from the boundary conditions?

These are the ASCII files you can request from your analysis to request different outputs.

https://www.dynasupport.com/howtos/general/forces-of-nodes

Are the trackers working well in the explicit case? Note that, you don't have to run an analysis for the entire time (13 secs in your case)...your results in explicit will still be valid as long as your kinetic energy is low compared to the internal energy. 

BTW, What keywords are you using to run an implicit analysis here? LS-DYNA Implicit is not supported by default in WB LS-DYNA 2020R1.

[novak1]

Hi.

The files rcforc and spcforc are generated in the directory, unfortunately, I don´t know how to load/export them into LSPP.
1. Switched the distributed solve with no positive results.

2.I have tried External Force and used boundry counditions velocity and displacement, but the results are inconclusive.
Trying Force Reaction and choosing the fixed support as the Boundry condition, I get an Error message (Extration Of Results has failed for: Force Reaction).

3.The trackers are not working in explicit either...

4.As per the Keywords, I am using the following set.

 

Do you have any other ideas as to why I am not able to read the desired results?

Thank you for your time.

[ramgopisetti]

From the above comments i had found out the you have no idea to work in LSPP, The LSDYNA solver will creat the d3plot , bndout,nodout and spcforc in the solver directory, All you need to know is drag and drop the d3plot [with no index file ] into lsprepost and use the ASCII option and click on load , once loaded it will show all respective components in the file and u can query them as per your demand. It is noted that u should have some level of understanding of the LSPREPOST. All the requeried files will we based on your demad by usign the database -> ascii_option & more significantly database->BINARY_D3PLOT entries.nCheers,All the bestn