Error in radioss

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

hi

 

i am getting an error what is the problem behind this my simulation goes on like this 

 

 

 ELAPSED TIME=        451.37 s  REMAINING TIME=     238056.46 s

 NC=    9500 T= 5.9868E-02 DT= 5.8914E-06 ERR= -0.5% DM/M= 0.0000E+00

 ELAPSED TIME=        476.10 s  REMAINING TIME=     238100.41 s

     RESTART FILES: bend_0001_[0001-0001].rst WRITTEN

 NC=   10000 T= 6.2957E-02 DT= 6.4528E-06 ERR= -0.6% DM/M= 0.0000E+00

 ELAPSED TIME=        500.97 s  REMAINING TIME=     238219.10 s

 NC=   10500 T= 6.6150E-02 DT= 5.8914E-06 ERR= -0.6% DM/M= 0.0000E+00

 ELAPSED TIME=        529.13 s  REMAINING TIME=     239438.85 s

 NC=   11000 T= 6.9340E-02 DT= 6.4528E-06 ERR= -0.6% DM/M= 0.0000E+00

 ELAPSED TIME=        557.75 s  REMAINING TIME=     240755.26 s

 NC=   11500 T= 7.2549E-02 DT= 6.4528E-06 ERR= -0.6% DM/M= 0.0000E+00

 ELAPSED TIME=        584.23 s  REMAINING TIME=     241002.99 s

 NC=   12000 T= 7.5685E-02 DT= 6.1558E-06 ERR= -0.6% DM/M= 0.0000E+00

 ELAPSED TIME=        612.67 s  REMAINING TIME=     242236.66 s

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Answers

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited January 2019

    Hi,

     

    the above simulation looks fine (energy and mass error, timestep evolution) and it is not obvious which error you are facing.

     

    Please share the model or at least the starter and engine *.out files.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited January 2019

    hi 

     

    remaining time is increasing there is no convergence 

     

    is this might be because of element size???

     

    i have done same simulation by applying steel property now i changed to aluminium this might because of time step and element size 

     

      

    Unable to find an attachment - read this blog

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited January 2019

    Please share the .0001.out

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited January 2019

    hi 

     

    thanks for replay 

    some where in unit system, element length & time step i might have made mistake i think 

    i used ton mm mpa s unit system 

     

    i made mistake in density it is 2.63e-9 please change that and check the model file...

     

    Unable to find an attachment - read this blog

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited January 2019

    Hi shrinaath 

    check   load applied,load curve,run time and material parameter 

    i have attached the file for  reference . modify your file as per your requirement ( file doesn't have updated material value )

     

    Unable to find an attachment - read this blog

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited January 2019

    @Shrinaath

     

    1. the error was because no Data: Var was defined for output blocks. 

    2. there are initial penetrations in the model (check with tool>penetration check).

    3. the model does not follow a consistent set of units (check HEADER_CARD)

    4. timestep imposed with mass scaling eas too high (leading to a high mass error).  Acceptable mass addition is in the 1-2% range.

    5. there is a possible incompatible kinematic condition. Plate_SPC is probably not constrained appropriately. 

    6. the remaining time increasing (from the first post) is due to the decrease in available computational resources (Windows Task Manager>processes>CPU) during computation- you probably opened some program that decreased available CPU. Remaining time increasing could also be because of timestep dropping (in your case it was stable) due to either contacts penalty stiffness or characteristic length of elements decreasing because of large deformation.

    Unable to find an attachment - read this blog