Learning Forum

[gcongdon]

I have a model where I am using *CONSTRAINED_SOLID_IN_SOLID_PENALTY to model anchors (solid elements) in a masonry wall (also solid elements). During analysis, a file "cbisfor" is written, which supposedly is writing the penalty forces between the constrained solids. However, I can't seem to open the file in LS PREPOST. In addition, the file is in binary as I am using MPP (quite a large model). 

Does anyone know how I can open/view the results included in the cbisfor file so that I can debug/verify adequate behavior out of my specified constraint? The file should be the same as the file written for CONSTRAINED_BEAM_IN_SOLID according to the manual. The file is presumably in LSDA format, but I don't know what that means precisiely. I tried opening this as "Fringe" data with LSDA format in LS PREPOST, but PREPOST just crashed when I try to do this. I am currently using LS PREPOST v4.8.11 which is supposed to be compatible with R12. From the manual section Capabilities to create LS-DYNA R11 in the Introduction:

*CONSTRAINED_BEAM_IN_SOLID:

• Add _PENALTY option to invoke a penalty-based formulation (implicit and explicit).
• Implicit support for IDIR = 1 (allow sliding along axial direction).
• Implicit support for AXFOR (user prescribed debonding force between beam and solid).
• Thermal solver recognizes *CONSTRAINED_BEAM_IN_SOLID by constraining temperature fields between beam and solid nodes.
• Write LSDA format output file named "cbisfor" containing debonding force (constraint-based) or penalty force (penalty-based). 

[Tonmoy]

Hi Greg!

I don’t have any experience in opening this kind of files. But, generally I open binary files in LSPP from upper ribbon>>FEM>>Post>>Binary Output.

If the file is in LSDA format, then you can convert it to ASCII to read the contents of the file using l2a: a program devs developed to do specifically the conversion. You can get more info in here: https://ftp.lstc.com/anonymous/outgoing/support/FAQ/ASCII_output_for_MPP_via_binout

For downloading the l2a (which is written to work using unix terminals), you can go to https://ftp.lstc.com/user/lsda/, use “user” as the user and “computer” as the password and then extract it to use it as described in the url above.

Thanks.

 

-Tonmoy.

 

Edit: Fixed broken urls.

 

[gcongdon]

Hi Tonmoy,

Thanks for your reply. Unfortunately, the second link you shared appears to be identical to the first link. Is this intentional? In addition, do you know if there is either a windows version of the tool or if there is a link to downloadable source that I can build on my machine?

Regards,

Greg

[Tonmoy]

Hi again Greg!

Sorry, that was unintentional and was a problem with my computer. I don’t think there is a windows version available, but you can either resort to CYGWIN or the newer windows subsystem for linux to use the tool. The tool is fairly simple and is explicitly described even for novices in the FAQ above.

Also, if you have the skill you can build from source provided in the url above. I didn't find any directions about it in the archieve though. 

[gcongdon]

Thank you! Apparently, in the latest version of the downloadable, there is a Python version as well as a C version of the program. The docs on how to use either are really sparse, but this should be all I need to get at the contents in the file hopefully. Otherwise I'll install the latest dev version of ls pre/post to see if they have added the functionality to open the filetype.