Not able to find the actual problem

Below is the archive file of my model.

https://drive.google.com/open?id=1IoE4wgJAWmKqIL6FGATcW8TVZhKPGMJD

Please suggest the solution for the problem.

Comments

  • peteroznewmanpeteroznewman Member
    edited October 2019

    Here is the ERROR I get on a big workstation.

     Number of equations was about 7.3 million.

     *** ERROR ***                           CP =     739.492   TIME= 08:11
     There is not enough memory for the Distributed Sparse Matrix Solver to 
     proceed using the out-of-core memory mode.  The total memory required  
     by all processes = 336902 MB.  The total physical memory that is       
     available on the system = 176879 MB.  Please decrease the model size,  
     or run this model on another system with more physical memory.  

    Looking at your model, you have too many elements, use a larger element size.

    You also have multiple contacts on the same surfaces. Delete all but the necessary ones.

    If I double the size of all mesh controls, it will solve on my workstation.

     DISTRIBUTED SPARSE MATRIX DIRECT SOLVER.
      Number of equations =     1201042,    Maximum wavefront =    552

      Total memory allocated for solver              =  90260.131 MB
      Total memory required for in-core solution     =  82303.980 MB
      Total memory required for out-of-core solution =  29984.555 MB

     The Distributed Sparse Matrix Solver is currently running in the       
     in-core memory mode.  This memory mode uses the most amount of memory  
     in order to avoid using the hard drive as much as possible, which most 
     often results in the fastest solution time.  This mode is recommended  
     if enough physical memory is present to accommodate all of the solver  
     data.                                                                    

    How much memory is installed in your computer?

  • SJ123SJ123 Member
    edited October 2019

    Hi Peter

    Thanks for looking at my model.

    The installed memory is 24 GB.

    If possible, could you please remove the unnecessary contacts from my model and upload it again. If not, suggest those unnecessary contact to be removed.

     

  • peteroznewmanpeteroznewman Member
    edited October 2019

    The version I edited will not run on your computer because it requires 30 GB of free memory and you have only 20 GB of free memory. You have to increase the element size even more.

    Most of the contacts labeled Contact were automatically generated and should be deleted. Look at each contact and see what surfaces light up and just keep the ones that are correct.

  • peteroznewmanpeteroznewman Member
    edited October 2019
  • GorgarGorgar Member
    edited October 2019

    Pteroznewman could you please, since I had to log in with my new email, because otherwise I am not able to log in even if I try to change my password, it says that I do not know the password, so I have now new email, but I am not able to find out all these ideas you have made for me with the oil that you were helping a month ago and before, so it looks a bit crazy, so do you know how to find your comments? Thanks for you ideas...Jiri

  • GorgarGorgar Member
    edited October 2019

    The main problem for me is to long in with my original email and it was [email protected], but it does not want to accept my password, but I know absolutely well the password! Thanks for your ideas, I just do not know how to log in by this email....

  • peteroznewmanpeteroznewman Member
    edited October 2019

    Jiri, sorry for your troubles.  Open a browser and go to Google.com in the search bar type this:

    site:studentcommunity.ansys.com Georgiro1 posted

    it will return a link to every post you have made.

  • SJ123SJ123 Member
    edited October 2019

    Hi Peter

    I have made changes suggested by you regarding the contact and element size but still, I am getting some error. Please help me out.

    Below is the link for the archive file of my model.

    https://drive.google.com/open?id=1ST93TEfvlnsS0jaAZVV7h7owj6WpBESg

  • GorgarGorgar Member
    edited October 2019

    Peter, thanks a lot, of course I do not know who shall I tell him the issue not to be able to log in?

    But thanks!

    Jiri

  • GorgarGorgar Member
    edited October 2019

    Peter, yes, I found it, this was the best. Thanks a lot!

    Jiri

  • peteroznewmanpeteroznewman Member
    edited October 2019

    Shobhit,

    I don't know why the solver is trying to run incore on a 24 GB memory machine when it calculated it needs 31 GB for incore.

    DISTRIBUTED SPARSE MATRIX DIRECT SOLVER.
      Number of equations =      752990,    Maximum wavefront =   4314

      Local memory allocated for solver              =   6804.421 MB
      Local memory required for in-core solution     =   6196.708 MB
      Local memory required for out-of-core solution =    751.710 MB

      Total memory allocated for solver              =  34117.895 MB
      Total memory required for in-core solution     =  31117.943 MB
      Total memory required for out-of-core solution =   4888.666 MB

     *** NOTE ***                            CP =      18.750   TIME= 22:12:1
     The Distributed Sparse Matrix Solver is currently running in the       
     in-core memory mode.  This memory mode uses the most amount of memory  
     in order to avoid using the hard drive as much as possible, which most 
     often results in the fastest solution time.  This mode is recommended  
     if enough physical memory is present to accommodate all of the solver  
     data.                                                                    

    Insert a command object to force it to run outofcore, pay attention to the double comma!

    DSPOPTION,,outofcore

    DISTRIBUTED SPARSE MATRIX DIRECT SOLVER.
      Number of equations =      752990,    Maximum wavefront =   4314

      Local memory allocated for solver              =   1843.666 MB
      Local memory required for in-core solution     =   5289.458 MB
      Local memory required for out-of-core solution =   1631.345 MB

      Total memory allocated for solver              =  10534.168 MB
      Total memory required for in-core solution     =  36135.412 MB
      Total memory required for out-of-core solution =   9367.275 MB

     *** WARNING ***                         CP =      43.805   TIME= 14:52:24
     The Distributed Sparse Matrix Solver is currently running in the       
     out-of-core memory mode.  This memory mode may provide significantly   
     worse performance compared to the in-core memory mode, depending on    
     the amount of available system memory and I/O speed.  Please monitor   
     the solver performance to ensure that the large amount of I/O to the   
     solver files does not create a bottleneck for performance.              
  • peteroznewmanpeteroznewman Member
    edited October 2019

    Under Analysis Settings, turn on Auto Time Stepping and set the initial substeps to 10.

    Under Solution Information, set the Newton-Raphson Residuals to 3.

    Why did you change the threads over to bonded contact?

     

  • SJ123SJ123 Member
    edited October 2019

    I have given the bonded contacts over the threads in order to simplify my model. Is it going to make much difference in the solution?

    Is it correct to give frictional contact over threads?

     

    I had made the changes suggested by you in my model but still getting an unknown error. Please help.

    Below is the archive file of my model.

    https://drive.google.com/open?id=1oZ8t96XqB0GfG1V7y4H6dGpgE95sMzI8

  • peteroznewmanpeteroznewman Member
    edited October 2019

    You did not insert a Command Object into the model.

    Click on Static Structural, then on the Environment tab click on the Commands button.

    Type the text shown.  Make sure to use two commas!

    DSPOPTION,,outofcore

    As I said above, your computer only has 24 GB of memory, and ANSYS should automatically choose outofcore, but it is wrongly choosing incore which requires > 30 GB of memory.


    What is the purpose of this analysis?  If it is to see the effect of the screw preload tension on the body under the screw head, you could get a good result much faster if you went back to CAD and sliced off the screw threads and the body they screw into at the plane where the cylindrical face of the screw ends. Just put a fixed support on the faces in that plane.  Now the model will solve much faster and you won't need the Command object, it will solve incore.

  • SJ123SJ123 Member
    edited October 2019

    Hi Peter

    This time I have changed the thread contacts to frictional one and Ansys has automatically chosen outofcore memory.

    But now I am getting some other error. Please have a look. 

    https://drive.google.com/open?id=1o9G9k22Oe16ULmjh2SMkBArT4o0g1UjW

  • peteroznewmanpeteroznewman Member
    edited October 2019

    Shobhit, you need to develop your own skills at diagnosing problems with ANSYS solutions.  The previous errors where the solver suddenly stops running because it runs out of memory are a bit more difficult to diagnose, but I helped you get past that. Take a look at the Solver Output from this latest solve, find the error and try to figure out what it means. Depending on the error, there are different remedies. Examples of how to get past them can be found on this site, but first you have to understand the error.

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