AUTO TIME Control

[Yaakov]

Hi everyone,

i want to define an auto time steps, like this:

a total of time is 1 second, mininal time step is +1e-6. what completely command DT should i write in input file?

best regards,
Jakob

[FEAP_Admin]

Please have a look in the manual for the AUTO command.

[Yaakov]

thanks very much for your answer,

i try this command for example Iex6 (thermo-mechanical) from Input dokuments, but it don't work  for this case

e.g.

BATCH
AUTO,DT,0.0000001,1
TRAN BACK
LOOP,,500
TIME,,50.0
LOOP,,15
TANG,,1
NEXT
PLOT CONT 3
NEXT

END

[K.Li]

Maybe you can try this,

Code: [Select]

BATCH
DT,, 0.1
AUTO, TIME, 5, 10, 6
AUTO, DT, 0.0000001, 1
....


[Yaakov]

Thanks for your answer,

Here, DT, ,0.1
        AUTO,DT,0.00000001, 1
      which meaning ist the DT Parameter for this case?
how can i define the sum of time in this case?

[K.Li]

This is described in the SOLUTION COMMAND MANUAL, check the command manual about "loop" and "AUTO time step". To set a total time, you can try this.

Code: [Select]

BATCH
  PARAM
  TRANs,BACK
  PLOT,DEFOrm
  PLOT,FACT,0.7 ! to keep plot in window
   DT,,dt
   AUTO, TIME, 5, 10, 6
    AUTO, DT, 0.0000001, 0.01 
  LOOP INFInite
   LOOP,,10
    TIME,, 0.6
    LOOP,,5     ! Note that at least 3 iterations
      TANG,,1   ! are needed to converge (since no
    NEXT        ! coupling tangent is included)
    PLOT,WIPE
    PLOT FRAM 1
    PLOT,RANG,0.4,0.9
    PLOT,CONT,3 ! Temperature contours
    PLOT FRAM 2
    PLOT,RANG,-1.0,0.2
    PLOT,STRE,1 ! 11-Stress contours
   NEXT
   FUNC,tinc
  NEXT
END
  DT = 0.0005


[Yaakov]

Hi Mr.Li and FEAP TEAM, thanks very much for your answer, with help of AUTO TIME and Loop my problem in this case  is clear now