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Frictional Braking Problem
3

Frictional Braking Problem

Frictional Braking Problem

(OP)
Hello,

According to the Abaqus Benchmark problems manual for Abaqus 6.9. A 60rad/s omega rotation has been applied  rigid disc in this problem attached below.  I can't see how this has been applied?  Any help would be much appreciated. I am trying to implement a similar simulation in my model at the moment, so trying to learn from this exmaple.

Thanks

Optieng

RE: Frictional Braking Problem

This is all just a guess.

I don't think it is applied.  I assume that you imported this from a INP file.  That function may not be supported by CAE.  

Write out an INP from this CAE file.  Use your favorite text editor to do a 'diff' command to see what has changed.

I hope this helps.

Rob Stupplebeen

RE: Frictional Braking Problem

As per Rob's message above, the keyword INITIAL CONDITIONS, TYPE=VELOCITY is not supported when importing an inp into CAE.

However, the keyword that *is* supported is INITIAL CONDITIONS, TYPE=ROTATING VELOCITY. You will have to go to the load module of Abaqus/CAE and create a new "Predefined Field". Make sure you select "Initial" for the Step to apply it in, and "Mechanical" for the category. The Velocity Type will then be available...

By the way, when you imported the inp file, there would have been a useful warning given (in the message area) regarding keyword support.  

RE: Frictional Braking Problem

(OP)
Thank-you very much for your responses.  I am not sure how I write out an input file from my CAE file?  Also, if the rotational velocity is not supplied in the input file, how else would the drum rotate without this input (the simulation shows the drum rotating during the time steps)?

Thanks again for your very valued inputs.

RE: Frictional Braking Problem

1. The rotational velocity is defined in the original inp file (provided in the braking2d_anl.inp sample file)

Here are the lines (excerpt from braking2d_anl.inp)
**  Start with it spinning at 60 rad/sec.
**
*BOUNDARY
 100, PINNED
*INITIAL CONDITIONS, TYPE=VELOCITY
 100, 6, 60.

Note that the above lines do not import correctly into Abaqus/CAE. That's the point of the previous post...

Many (most) of the examples provided as inp (especially the ones with trivial geometry) were crafted by hand rather than using Abaqus/CAE, and might have been done so years before Abaqus/CAE existed. You can run all these models without going through Abaqus/CAE but just issuing a command like  "abaqus braking2d_anl" from a command window/terminal.


2. CAE writes an input file everytime you submit a job (check your working directory). Alternatively you can just create the inp without executing the job. Look in the Job moddule - Job Manager... Or if you want to do hand edits (e.g., to insert keywords that are not supported) you can pull up the keyword editor (Model - Edit keywords - <choose the model>) BTW keyword coverage is pretty good these days, check the help docs for what is and is not covered.

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