Problems setting up a time step counter , Transient dynamic analysis

[vinny31]

Hi

I wish to change the size of the time step “(dt) from 0.01us to 0.5 us” when I reach a desired time, called “Timef =1.0us” during a transient dynamic analysis!

I am happy with the time parameters I set out below, but the problem I am specifically having is setting up a time step counter “ctime” to count each time step of a transient analysis.
Can anyone suggest how I would set up a scalar time counter for the “ctime” parameter below? I believe that once I can define this parameter, then the changes of time step “dt” will also work!

I am using the following parameters.

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Genereal model time stepping parameters
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

dt = 0.01 ! Time step size
idt = dt ! Initial time step size
twait = 0.0 ! Wait time before sim begins (removes initial transient noise)
timep = 0.1 ! Pulse duration
timem = 6.0 !Time simulation continues after pulse
timef = timem+timep+twait ! Total simulation time


nt = (timef-0.1*dt)/dt+1 ! number of time steps
ndt = 10000

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Setting up a time counter to count time (the next two
line are the problem)
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
ctime=???? ! Time counter

!*do,ctime,dt,nt,dt




!!!!!!!!Change of time Step size!!!!!!!!!!!!!!!!

*if,ctime,lt,1.0,then

FLDATA4,TIME,step,0.01

*else

FLDATA4,TIME,step,0.5

*endif
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!




Regards
V

 

[cbrn]

Hi,
provided that you don't use "Auto Time Step", i.e. the assumption of fixed number of time steps will never be violated, you can determine the current timestep based upon the cumulative number of loadsteps / substeps:
*GET,cumloadsteps,ACTIVE,,SOLU,NCMLS
*GET,numsubs,ACTIVE,,SOLU,NCMSS

Regards