Learning Forum

[Baloch]

Dear All,

I am using a python script to control longitudinal spring in transient analysis. How I can make it sure whether the script is working or not? Because when I run the problem and looking into solver output there is no information in the solver out put about the script.

[Erik Kostson]

Hi

I would try to run a simple test case (as shown below), where you use this script, and thus expect a certain behaviour.

So say the spring changes stiffness halfway through the analysis (say from 1 N/mm to 2 N/mm at time 9.5 sec.) then in the spring probe for the spring which is just attached to a block which is being pulled by a constant displacement (1 mm), we should see the force in the spring doubling from 1 N to 2 N, just as shown below so that is a simple example on how to see that the script (apdl to have time dependent stiffness) works.
Of course one can create many different type of tests so this is just a simple one for reference, and in order to explain how one can check if a script does what it is supposed to do.

All the best

Erik

[Baloch]

Dear
If possible can you share a snap of the apdl script you used?

[Erik Kostson]

Hi

See this post where the snippet is shown - the only difference here is tha the *dim array kfreq should be a function of time not frequency,
so the array is ktime called say and defined as:
*DIM,ktime,table,5,1,,TIME
RMODIF,_sid,1,%ktime%

Of course you need to assign the appropriate values to ktime just as is done in that post for kfreq - of course you need your own time and stiffness values, this is just for reference.
For more info see the *DIM, and RMODIF commands.

All the best

Erik